Merge pull request #221 from excaliburjs/dev-erik

Merge #207 directory restructure into master
Update CONTRIBUTING.md
Merge pull request #222 from excaliburjs/dev-erik

Collision grouping and particle demo for start/end size
Close #177 Renamed and public may need to live off of camera
Reorganize directory structure per suggestion in #207
Update bower and npm package
Update CONTRIBUTING.md
Close #100 collision grouping implemented
Closes #218 Added particle startSize and endSize to particle tester
Merge pull request #223 from excaliburjs/dev-erik

Closes #215 enterviewport and exitviewport events are implemented
Merge pull request #225 from excaliburjs/dev-erik

Closes #224 Implemented OnInitialize and 'initialize'
Merge pull request #227 from excaliburjs/dev-erik

Fixes #226 actor.kill behaves unexpectedly when called multiple times on...
Merge pull request #230 from excaliburjs/dev-erik

Merge collision fixes
resolving merge
added 'die' action

allows for an actor to be removed from the scene only after completing
the previous actions in its action queue
Merge pull request #231 from excaliburjs/dev-josh

added 'die' action
Fix VS2013 solution; Chutzpah 3.2 support
Remove game.js
Merge branch 'master' of github.com:eonarheim/Excalibur into dev-erik