Added UIElement header, source, and test file. Changed respective CMakeList files, and Bakge.h
Added UIHoverable interface
Added override to Node's SetPosition()
Added UIElement SetPositionTest
Updated uitest for SetPosition
Added TestEngine implementation to uitest
Added Rectangle::AllocateGLBuffers()
Merged Rectangle code
Added UIElement::Create()
Added fixes to UI
UIElement now renders
Now using camera to set the view and perspective
Cube now uses Camera
Added UIContainer skeleton
Added UIContainer members
Added UI Interfaces
Added operator[] to UIContainer
Removed UIContainer, added parameter to UIContainer::RemoveElement, removed CMakeList entry
Changes to UIContainer and uitest
UI*: Whitespaces fixes