Remove getter/setter ie8 fallbacks
Remove old IE specific filter code from DOM.js
Remove IE6 background hack
Remove documentation note about ie8
Remove IE8 specific rotation code and setup
Remove IE8 test logic
extracted code from extensions.js

moved keys & mouseButtons to keycodes.js
moved zeroFill to 2D.js (only 2D.js uses zeroFill)
fix jump while falling

fixes #419
Merge pull request #657 from starwed/kill-ie8

Kill ie8 specific code in Crafty
Allow visibility MBR to be set manually

This patch adds properites to "2D" that indicate how far beyond an object's default dimensions the visible MBR should be.

These can be set with the method offsetBoundary.
Merge pull request #658 from starwed/manual-mbr

Allow visibility MBR to be manually offset
Merge pull request #660 from mucaho/split_files_1

extracted code from extensions.js
Merge pull request #662 from mucaho/fix_jump_falling

fix jump while falling
Fix problem with DOM sprite animation in webkit browsers

The backgroundPosition CSS attribute isn't always getting set correctly in Safari.  This seems to be some sort of hard to trigger webkit-only bug that occurs when we do sprite animation, but not when setting regular sprite positions.

I was unable to produce a simple test case without using Crafty, so I'm not sure what the exact problem is.  This "fixes" things by setting the background position separately from the rest of the background properties.
Merge pull request #664 from starwed/safari-dom-sprite

Fix problem with DOM sprite animation in webkit browsers