Copter: fix to dcm-check to be continuous

dcm-check was triggering after 10 bad headings but these did not need to
be continuous meaning if the vehicle was flown long enough it would
almost certainly trigger a dcm-check failure and land
AP_InertialSensor: fixed timer bug in HIL sensors
Copter: ReleaseNotes for AC3.2-rc14
Copter: update version to AC3.2-rc14
Merge remote-tracking branch 'diydrones/ArduCopter-3.2' into
ArduCopter-3.2