very nice proper magnetometer vector rotation from crashpilot1000

git-svn-id: https://afrodevices.googlecode.com/svn/trunk/baseflight@261 7c89a4a9-59b9-e629-4cfe-3a2d53b20e61
further accuracy improvement for mag calculation.

git-svn-id: https://afrodevices.googlecode.com/svn/trunk/baseflight@263 7c89a4a9-59b9-e629-4cfe-3a2d53b20e61
Default config changes
Merge branch 'upstream' of https://github.com/multiwii/baseflight