Sprayer: minor change to flags type
Copter Motors: add slow start feature

Combined armed, frame orientation and slow_start into flags bitmask
Removed ability to set max throttle because it was never used
Re-ordered class variables
Copter: removed calls to set motor's max throttle
Copter: integrate slow start feature
Copter: #define for initial altitude jump during take-off

Developers can add a line like to APM_Config.h to reduce the initial
jump when taking off in Loiter or AltHold flightmodes:
#define ALT_HOLD_TAKEOFF_JUMP 0