added per-body timeScale
constraints now account for timeScale
added Body.scale
added Body.setStatic
removed Body.updateProperties (now a private method)
added Vector.angle
added Query module, added Query.ray
added raycasting demo
fixed some issues with engine.timeScale
changed engine.timeScale to engine.timing.timeScale
moved event documentation to end of file for clarity
added world file saving and loading to Gui
fixed an issue with timing.timeScale when at 0
refactored Matter.Gui
moved Gui.js into src/tools/Gui.js
added Composite.get
added labels to bodies, constraints and composites
updated resurrect.js
refactored Mater.Gui
initial commit of Matter.Inspector