Code Cleanup

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2014-09-21 : v0.8.1
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* Added: README now lists minimum requirements
* Changed: README updated with new collision system
* Changed: Map:enableCollision() renamed to Map:initWorldCollision()
* Changed: Map:drawCollisionMap() renamed to Map:drawWorldCollision()
* Changed: Updated framework files (still no real Lua/Corona support)
* Changed: Tidied up collision code
* Removed: Map:getCollisionMap()