Added Lerpable interface +
lerp function for classes implementing Lerpable.
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
Refactored headless environment
Merge remote-tracking branch 'movingblocks/develop' into develop
Fixed style warnings
Moved Profiler to src/dev
Refactored WorldAtlas into interface and implementation
fixed bt editor layout
editor now opens using F5
Added annotation to mark valid WorldGeneratorPlugin classes for registration.
Removed support for annotations in modules (wasn't possibly to properly support within sandbox restrictions)
Added permission for WorldGeneratorPluginLibrary.
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