Removed unneeded variables in main.cpp for pitch,yaw.  Renamed routines to make it more clear where gyros are being read.  Re-enabled marker box being driven by head gyros.
Merge branch 'master' of https://github.com/worklist/hifi
Improved SerialInterface:  Added gravity vector get function, closer to coding standards, better rendering of levels.
Merge pull request #47 from PhilipRosedale/master

Cleanup and partial re-enabling of head gyros