DataFlash: start to fix example build
autotest: fixed python path for mavtemplate
build: add 1280 build for rover and plane
build: added support for "make apm1-1280"
autotest: fixed mavlink paths
Plane: fixed MAVLink target IDs in fence point message

thanks to Kevin Hester for finding this
autotest: add 10 mins to timeout

this copes with build_binaries.sh
build: record git version in firmware build
DataFlash: report log number when starting a new log

helps with test sketch
DataFlash: fixed test sketch build and run
Rover: implement RSSI_PIN

route RSSI value from receiver to MAVLink
AP_HAL: update AnalogIn example to show voltages not raw values
Rover: remove scaling of voltage pin
autotest: added skid steering support to rover simulator

Very rough initial implementation. Needs to be tweaked for more
realistic behaviour later.

thanks to Greg Brill for pointers on this.
autotest: added skid steering version of rover sim start script
Rover: initial implementation of skid steering for APMrover2

this adds SKID_STEER_IN and SKID_STEER_OUT parameters for controlling
skid skeering control and output
autotest: improved skid steering test scripts
Copter: remove unused GPS and baro filters

Saves 24bytes of RAM
Removing the baro filter leads to noisier Baro Alt appearing in the log
so we should make the inertial nav altitude appear in the CTUN message
Copter: rename failsafe to failsafe_radio

Makes way for separation of failsafes for throttle, gps and gcs
Copter: GPS Failsafe implemented

Switches to LAND mode 5 seconds after losing GPS if you're in a flight
mode that requires a GPS