Added beginnings of inventory screen.
Improved rendering of mesh in UI.
Added commands to reload shaders and materials.
Merge branch 'develop' into nui

Conflicts:
	engine/src/main/resources/assets/skins/default.skin
Added tooltips to inventory cells.
Merge branch 'develop' into nui
Added stack count display to inventory cell.
Merge branch 'develop' of git@github.com:MovingBlocks/Terasology.git into nui
Completed basic inventory in NUI.
Removed some unnecessary debugging code
Merge branch 'develop' into nui
Fixed display of double-sided block mesh items.
Added support for arbitrary cursor attachments
improved handling of not loadable trees
Merge branch 'develop' into nui
Added generic linear interpolation objects and functions
Added modulus and remainder to Teramath.
added heightOffset to SkeletalMeshComponent, to allow vertical positioning of meshes
added tooltips
Merge remote-tracking branch 'upstream/develop' into develop
Merge remote-tracking branch 'upstream/develop' into behavior
fixed timer node.
added property annotations.
fixed copyright
Merge remote-tracking branch 'upstream/develop' into behavior