Copter: move CIRCLE_RADIUS definition
Copter: SPORT mode to use alt hold
Copter: configurable max lean angle

ANGLE_MAX parameter allows limiting the roll and pitch angles during
manual and auto flight modes to anywhere from 10 to 80 degrees
Copter: angle limiter fix for max lean angle
Copter: Leonard's sport fix re slow roll
Merge remote-tracking branch 'diydrones/master'