This should obsolete AP_GPS_HIL as it's a little more versatile (and it will generate cheaper code).
git-svn-id: https://arducopter.googlecode.com/svn/trunk@1336 f9c3cf11-9bcb-44bc-f272-b75c42450872
Nuke AP_GPS_IMU, as nothing is using it anymore.
Simplify the handling of no GPS/no fix detection.
Fix prototypes for ::init and ::read.
Update AP_GPS_Auto and corresponding example, nearly ready for primetime.
Use uint8_t rather than byte.
Strip some _error() calls to save space. More could still go.
git-svn-id: https://arducopter.googlecode.com/svn/trunk@1246 f9c3cf11-9bcb-44bc-f272-b75c42450872
Note that this is currently disabled as changes need to be made to APM to support it.
Tested with MTK, u-blox and SiRF GPS'.
git-svn-id: https://arducopter.googlecode.com/svn/trunk@671 f9c3cf11-9bcb-44bc-f272-b75c42450872