HAL_AVR: fixed example build
DataFlash: slight efficiency improvement

fixes issue #314

thanks Dongfang!
Copter: remove stabilize's call to calc I terms

I terms all moved to rate controllers so this will be a small
performance improvement
Copter: remove throttle rate's I and D calcs
Copter Motors: remove old style stability patch
Copter: Move CH7 - CH8 check from read_aux_switches() to pre_arm_checks.

Moving this to pre-arm checks save some processing time and is safer.
RC_Channel: rename 'Manual' to RCPassThru

this should make it clearer what it does
AP_Scheduler: added load_average() function

useful to give a load average in SYS_STATUS mavlink message
APM_Control: set a small D value by default

0.02 may help with some planes that have slow response

Pair-Programmed-With: Paul Riseborough <p_riseborough@live.com.au>
Copter Fence: reduce circle @Range to 30m
Copter: add flags for upper and lower throttle limits

Freeze desired altitude when motors hit a limit
Copter: reset loiter target when landed
Copter: bug fix for take-off in loiter
Copter: clear thr accel I term on take-off
Copter: allow arming in AltHold and Loiter if landed
Copter: landing check changes
Copter Motors: by default spin motors at 65 when armed
Copter: turn off stability patch when landed in Loiter
Copter: remove landing checks in loiter controller
Copter: deactivate accel throttle controller when landed