RC: set dead zone only if parameter has not been set by user
Plane: set_dead_zone renamed to set_default_dead_zone

Change in use of parameter means value passed in should be 1/2 what it
was previously
Rover: set_dead_zone renamed to set_default_dead_zone

Change in use of parameter means value passed in should be 1/2 what it
was previously
Copter: set_dead_zone renamed to set_default_dead_zone

Dead zones now set as part of rc initialisation instead of only after
eeprom is erased.
Change in use of parameter means value passed in should be 1/2 what it
was previously
RC: example sketch uses set_default_dead_zone
AP_TECS: compile error fix for size_of(log_tuning)