Fixed RC calibration trim problem.  Trim was not being set because setTrimPositions() was never being called.
Merge pull request #328 from gefink/master

Fixed RC calibration trim problem
Added Set Home option to map menu. Fix home icon always placed in bottom right.
Fixed obtaining position. Fixed message box text.
Merge pull request #331 from dagoodma/set_home

Set home
Merge branch 'master' of github.com:mavlink/qgroundcontrol into config