- consider I2C_GPS as a simple GPS device like SERIAL GPS: the same code is now used for all GPS devices. (best option to keep old I2C GPS compatibility, but code size with GPS is now an issue with pro micro proc)
- make HEADFREE optional
- use struct to serialize GPS data in MSP part

git-svn-id: http://multiwii.googlecode.com/svn/trunk/MultiWii_shared@1666 02679b44-d973-9852-f2fa-63770883b36c