palette is now a UIList
nodes can be collapsed/expanded using right mouse click
copy subtrees using SHIFT
link subtrees using SHIFT, does not work fully
Merge remote-tracking branch 'upstream/develop' into behavior
updated to latest changes
Tasks are now injected
Merge remote-tracking branch 'upstream/develop' into behavior

Conflicts:
	engine/src/main/java/org/terasology/logic/players/MenuControlSystem.java
fixed bt editor layout
editor now opens using F5
refactored Task and Interpreter
Stopping a task now stops all tasks, that were started by the task.
Merge remote-tracking branch 'upstream/develop' into behavior

Conflicts:
	engine/src/main/java/org/terasology/logic/behavior/nui/BehaviorTreeEditorSystem.java
Remove lwjgl dependencies from Texture
added some icons
Merge pull request #859 from synopia/behavior

added some icons
Merge pull request #856 from mkienenb/remove-lwjgl-deps-texture

Remove lwjgl dependencies from Texture
Implemented NUI based loading screen.
Merge branch 'develop' of git@github.com:MovingBlocks/Terasology.git into develop
Removed InGameNUIRenderSystem again.
Removed BehaviorTreeEditorSystem unnecessarily closing screens.
Deprecated NullIterator - can use Collections.emptyIterator() or Collections.emptyList() instead.
Removed old loading screen.