Added play music node
Merge remote-tracking branch 'upstream/develop' into behavior
fixed miglayout and added @API to WorldAtlas
fixed music and sound node
added a global entity to run music node
Merge remote-tracking branch 'upstream/develop' into behavior
Only one global entity can be exist
Added AudioEndListener, so PlaySound/Music nodes switch from RUNNING to SUCCESS, once the sound/music ends.
Updated description in prefab
Merge remote-tracking branch 'upstream/develop' into behavior

Conflicts:
	engine/src/main/java/org/terasology/logic/behavior/BehaviorSystem.java
fixed bug in PostBeginSystems
AutoCreate to create a global entity for the default behavior tree
Removed API from WorldAtlas
ZoomableLayout can now zoom
Merge remote-tracking branch 'upstream/develop' into behavior
AudioEndListeners are now registered per sound/music play
removed log message
added framebuffer to canvas
Fixed clicking on the scrollbar to skip to a location.
Switched breath bar over to NUI.
Moved Crosshair to NUI.
Await shutdown of chunk generation pipeline.
Removed old GUI code.