Enables controlling UI forms with a gamepad.  Adds a few things to the forms test in order to test
this feature.
Merge branch 'next' of https://github.com/blackberry/GamePlay into next

Conflicts:
	gameplay/src/Control.cpp
Tweaks to the way gamepads change focus within containers.
Tweaks and fixes to Container behavior when a gamepad is used to interact with a form.
Modifications to the FormsTest and TestsGame in order to better support gamepads in the test app.
Keeping the lua bindings up-to-date.
Merge branch 'next' of https://github.com/blackberry/GamePlay into next
Minimal modifications to ParticlesGame and RacerGame so that their menus are usable with a gamepad.
Change to sliders so that they consume all gamepad events while active.
Adding a few missing API comments.
Using Gamepad setters from PlatformBlackBerry so that gamepad events are triggered on BB10, enabling UI control.
Using the correct Gamepad setters from PlatformMacOS so that events are triggered.
Merge pull request #925 from ablake/next

Enables interaction with UI forms using gamepads.