improved test sphere collision algorithm
Merge remote-tracking branch 'upstream/master'
Cleaned up some const values in Head.h, implemented avatar gravity and ground collision, improved test sphere collision, added _usingBodySprings test to getHeadPosition, improved camera settings in main.cpp, cleaned up commented-out code in main.cpp
Merge remote-tracking branch 'upstream/master'
improved rendering of avatar
Merge remote-tracking branch 'upstream/master'
Merge pull request #106 from Ventrella/master

Improved avatar rendering