Throw an exception if the given easing function is not valid

should help tracking down issues when upgrading to last version of
melonjs (and the new embedded tween library version)
[#59] simplified and fixed the logic for `auto-sort`, and added a flag to enable/disable recursive sorting (off by default)
Fixed debugPanel installation when `#debug` is defined
Moved debug draw operation to the debugPanel
Also move the two corresponding debug flag to the debug panel

2 more to kill !
[#108] also moved the fps counting to the debugPanel

FPS information is now only available through the debug panel object
(and not anymore through the HTML element)

(Only one left now : me.debug.renderCollisionMap!)
set binary load to async, and removed the usage of dataType
Improves build process and linting
Merge pull request #270 from nvlbg/master

Improves build process and linting (by nvlbg)
Merge pull request #268 from agmcleod/feature/fix-preloadbinary

set binary load to async, and removed the usage of dataType (by agmcleod)
Fixed `_pauseTime` not being defined

thanks to the new lint task ! They are tons of other reported issues,
but global variables are always bad :)
Fixed a regression in the isometric renderer

following changes in the following commit :
https://github.com/melonjs/melonJS/commit/dd6af60165ee42fd58883250a671c5ceae5908d9
[#54] jslint - fixed a few easy ones
[#271] fixed the `worldToScreen` function
[#54] freed `texturepacker,js` and `GUI.js` from the lint report ;)

magically these two ones are perfect !
Merge branch 'master' into ticket-103-clean

Conflicts:
	Gruntfile.js
	examples/platformer/js/game.js
	src/debug/debug.js
	src/level/TMXLayer.js