[Breaking] Consolidate screenBackgroundColor and orientation to layout node

screenBackgroundColor was also renamed to backgroundColor

```js
layout: {
  orientation: 'landscape',
  backgroundColor: 'red'
}
```

lib/android/app/src/main/java/com/reactnativenavigation/parse/LayoutOptions.java

+package com.reactnativenavigation.parse;
+
+import com.reactnativenavigation.parse.params.Color;
+import com.reactnativenavigation.parse.params.NullColor;
+import com.reactnativenavigation.parse.params.NullNumber;
+import com.reactnativenavigation.parse.params.Number;
+import com.reactnativenavigation.parse.parsers.ColorParser;
+import com.reactnativenavigation.parse.parsers.NumberParser;
+
+import org.json.JSONObject;
+
+public class LayoutOptions {
+    public static LayoutOptions parse(JSONObject json) {
+        LayoutOptions result = new LayoutOptions();
+        if (json == null) return result;
+
+        result.backgroundColor = ColorParser.parse(json, "backgroundColor");
+        result.topMargin = NumberParser.parse(json, "topMargin");
+        result.orientation = OrientationOptions.parse(json);
+
+        return result;
+    }
+
+    public Color backgroundColor = new NullColor();
+    public Number topMargin = new NullNumber();
+    public OrientationOptions orientation = new OrientationOptions();
+
+    public void mergeWith(LayoutOptions other) {
+        if (other.backgroundColor.hasValue()) backgroundColor = other.backgroundColor;
+        if (other.topMargin.hasValue()) topMargin = other.topMargin;
+        if (other.orientation.hasValue()) orientation = other.orientation;
+
+    }
+
+    public void mergeWithDefault(LayoutOptions defaultOptions) {
+        if (!backgroundColor.hasValue()) backgroundColor = defaultOptions.backgroundColor;
+        if (!topMargin.hasValue()) topMargin = defaultOptions.topMargin;
+        if (!orientation.hasValue()) orientation = defaultOptions.orientation;
+    }
+}

lib/android/app/src/main/java/com/reactnativenavigation/parse/Options.java

         Options result = new Options();
         if (json == null) return result.withDefaultOptions(defaultOptions);
 
-        result.orientationOptions = OrientationOptions.parse(json);
         result.topBar = TopBarOptions.parse(typefaceManager, json.optJSONObject("topBar"));
         result.topTabsOptions = TopTabsOptions.parse(json.optJSONObject("topTabs"));
         result.topTabOptions = TopTabOptions.parse(typefaceManager, json.optJSONObject("topTab"));
         result.screenBackgroundColor = ColorParser.parse(json, "screenBackgroundColor");
         result.modal = ModalOptions.parse(json);
         result.statusBar = StatusBarOptions.parse(json.optJSONObject("statusBar"));
+        result.layout = LayoutOptions.parse(json.optJSONObject("layout"));
 
         return result.withDefaultOptions(defaultOptions);
     }
 
-    @NonNull public OrientationOptions orientationOptions = new OrientationOptions();
     @NonNull public TopBarOptions topBar = new TopBarOptions();
     @NonNull public TopTabsOptions topTabsOptions = new TopTabsOptions();
     @NonNull public TopTabOptions topTabOptions = new TopTabOptions();
     @NonNull public Color screenBackgroundColor = new NullColor();
     @NonNull public ModalOptions modal = new ModalOptions();
     @NonNull public StatusBarOptions statusBar = new StatusBarOptions();
+    @NonNull public LayoutOptions layout = new LayoutOptions();
 
     void setTopTabIndex(int i) {
         topTabOptions.tabIndex = i;
     @CheckResult
     public Options copy() {
         Options result = new Options();
-        result.orientationOptions.mergeWith(orientationOptions);
         result.topBar.mergeWith(topBar);
         result.topTabsOptions.mergeWith(topTabsOptions);
         result.topTabOptions.mergeWith(topTabOptions);
         result.screenBackgroundColor = screenBackgroundColor;
         result.modal.mergeWith(modal);
         result.statusBar.mergeWith(statusBar);
+        result.layout.mergeWith(layout);
         return result;
     }
 
     @CheckResult
 	public Options mergeWith(final Options other) {
         Options result = copy();
-        result.orientationOptions.mergeWith(other.orientationOptions);
         result.topBar.mergeWith(other.topBar);
         result.topTabsOptions.mergeWith(other.topTabsOptions);
         result.topTabOptions.mergeWith(other.topTabOptions);
         if (other.screenBackgroundColor.hasValue()) result.screenBackgroundColor = other.screenBackgroundColor;
         result.modal.mergeWith(other.modal);
         result.statusBar.mergeWith(other.statusBar);
+        result.layout.mergeWith(other.layout);
         return result;
     }
 
     Options withDefaultOptions(final Options defaultOptions) {
-        orientationOptions.mergeWithDefault(defaultOptions.orientationOptions);
         topBar.mergeWithDefault(defaultOptions.topBar);
         topTabOptions.mergeWithDefault(defaultOptions.topTabOptions);
         topTabsOptions.mergeWithDefault(defaultOptions.topTabsOptions);
         if (!screenBackgroundColor.hasValue()) screenBackgroundColor = defaultOptions.screenBackgroundColor;
         modal.mergeWithDefault(defaultOptions.modal);
         statusBar.mergeWithDefault(defaultOptions.statusBar);
+        layout.mergeWithDefault(defaultOptions.layout);
         return this;
     }
 

lib/android/app/src/main/java/com/reactnativenavigation/parse/OrientationOptions.java

         }
     }
 
-    public void mergeWith(OrientationOptions other) {
-        if (other.hasValue()) orientations = other.orientations;
-    }
-
     public boolean hasValue() {
         return !orientations.isEmpty();
     }
 
-    public void mergeWithDefault(OrientationOptions defaultOptions) {
-        if (!hasValue()) orientations = defaultOptions.orientations;
-    }
-
     @Override
     public String toString() {
         return hasValue() ? Arrays.toString(orientations.toArray(new Orientation[0])) : Orientation.Default.toString();

lib/android/app/src/main/java/com/reactnativenavigation/presentation/OptionsPresenter.java

     }
 
     public void present(View view, Options options) {
-        applyOrientation(options.orientationOptions);
+        applyOrientation(options.layout.orientation);
         applyViewOptions(view, options);
         applyStatusBarOptions(view, options.statusBar);
     }

lib/android/app/src/main/java/com/reactnativenavigation/presentation/StackOptionsPresenter.java

     }
 
     public void applyChildOptions(Options options, Component child) {
-        applyOrientation(options.orientationOptions);
+        applyOrientation(options.layout.orientation);
         applyButtons(options.topBar.leftButtons, options.topBar.rightButtons);
         applyTopBarOptions(options.topBar, options.animations, child, options);
         applyTopTabsOptions(options.topTabsOptions);
     }
 
     public void mergeChildOptions(Options options, Component child) {
-        mergeOrientation(options.orientationOptions);
+        mergeOrientation(options.layout.orientation);
         mergeButtons(options.topBar.leftButtons, options.topBar.rightButtons);
         mergeTopBarOptions(options.topBar, options.animations, child);
         mergeTopTabsOptions(options.topTabsOptions);

lib/android/app/src/main/java/com/reactnativenavigation/views/StackLayout.java

     }
 
     public void applyChildOptions(Options options) {
-        optionsPresenter.applyOrientation(options.orientationOptions);
+        optionsPresenter.applyOrientation(options.layout.orientation);
     }
 
     public void applyChildOptions(Options options, Component child) {

lib/android/app/src/test/java/com/reactnativenavigation/viewcontrollers/OptionsMergingTest.java

         verify(uut, times(0)).applyOrientation(any());
 
         JSONObject orientation = new JSONObject().put("orientation", "landscape");
-        options.orientationOptions = OrientationOptions.parse(orientation);
+        options.layout.orientation = OrientationOptions.parse(orientation);
         uut.mergeChildOptions(options, child);
-        verify(uut, times(1)).applyOrientation(options.orientationOptions);
+        verify(uut, times(1)).applyOrientation(options.layout.orientation);
     }
 
     @Test

playground/src/screens/ModalScreen.js

         drawBehind: true,
         backgroundColor: 'transparent'
       },
-      orientation: ['portrait']
+      layout: {
+        orientation: ['portrait']
+      }
     };
   }
 

playground/src/screens/OrientationDetectScreen.js

     this.detectHorizontal = this.detectHorizontal.bind(this);
     this.state = { horizontal: false };
     Navigation.mergeOptions(this.props.componentId, {
-      orientation: props.orientation
+      layout: {
+        orientation: props.orientation
+      }
     });
   }