committing to merge with new changes
added head and foot buttons to player and improved jump mechanics
Merge branch 'master' of https://github.com/SDSMTGDT/Physicist
stashing changes for a big merge.
fixed code analysis issues, added collision categories and finalized head and foot sensor implementation for player mechanics.
fixed issues noted in pull request
added validation in the SensorBody setter, moved an offset-fixing function to the Actor from the player, and fixed the horizontal movement dampening for the player when on the ground.
moved sprite fixing for rotation over to the actor and implemented it.  Works well at 180 degree rotation and slightly well at 90 and 270 rotation... the offset issue is still present.  Also fixed a player movement bug where left movement was adversely modififying the player's velocity.
replaced upKey with jumpKey
merged changes
fixed collision category issues
Merge pull request #48 from Porkenstein/master

Added improved player mechanics, physicist categories, and improved proximity triggers.