Fixed sample builds for Android

Default target for Android builds is armeabi-v7a for a while, updated
the samples to build with that.
Merge pull request #1112 from rgngl/samplesAndroidFix

Fixed sample builds for Android
- Fixed an error in Matrix::createOrthographicOffCenter.
- Changed orthographic camera mode to have an origin of bottom left, with +Y up and +X to the right.
- Added configurable character spacing to the Font class.
- Changed Scene:addNode and Node:addChild to add nodes to the back of the list instead of the front, so that traversal order matches the order in which nodes are added.
- Added support for creating hierarchy (child nodes) in a .scene file.
Merge branch 'next' of https://github.com/blackberry/GamePlay into next

Conflicts:
	gameplay/src/TextBox.cpp
Merge pull request #1119 from sgrenier/next

Misc changes and fixes
Updated some of the form Control classes so that they get marked as dirty when modified.
Merge pull request #1120 from dgough/next

Updated some of the form Control classes so that they get marked as dirty when modified