Added some rocks for random generated background test.
Add contact listener; use the PreSolve callback to detect collision between player and door
added idle animation and center camera on character
jump check1

WIP
door animation frames
Better camera movement
update author list
Merge branch 'master' of https://github.com/cookingclub/polarity into state-objects-audio

Conflicts:
	physics/behavior.cpp
	world/world.cpp
	world/world.hpp