Add curly braces around the visible property

The bottomTab settings were not being properly applied if a SplitView
controller was nested. Part of this seems to be that the 'options' for
SplitView were in their V1 form, i.e. they did not have access to the
full topBar/bottomTab/etc.

I refactored the options to be in their own subsettings. NOTE: the
settings for splitView are not being applied currently -- they weren't
before and they still are not now.

With access to the full options now, I was able to change
RNNSplitViewController to properly override
willMoveToParentViewController to get the bottomTab icon to properly
show up.

"more then one screen" should be "more than one screen"

title was renamed to text

* Work in progress

* Arbitary changes

* Improvements on API

* Cleanup RNNSplitViewController, allow mergeOptions

* Added documentation and better playground example

* Adding tests for coverage

* Find out why this test is failing.

* Only show split view on iOS

* Add test back in

* Initial commit

* Initial commit

* Clean-up title