Commiting before cherry-pick
added unloading of scenes in scene graphs and made the main menu load the game

Conflicts:
	VajraFramework/ExampleGame/Code/ExampleGame/Ui/TouchHandlers/MainMenuTouchHandlers.cpp
	VajraFramework/Vajra/Engine/SceneLoaders/UiSceneLoader/UiSceneLoader.cpp
Added MainMenu
added support for touch up on UIObjects and stop touch tracking when touch is moved off an object
play button starts game
Merge branch 'master' into main-menu
Temp fix for visibilty propogation when scenes are loaded
Register and Unregister UIObjects based on clickable and visible
Mainmenu switches between different screens
removed log messages
mend
InGame menu
Postgame screen placeholder
Merge branch 'master' into main-menu

Conflicts:
	VajraFramework/ExampleGame/Code/ExampleGame/Test/TestFile.cpp
Merge branch 'master' into main-menu
Load the new scene with the menu
Merge pull request #51 from VajraFramework/main-menu

Main menu