GPS: integrate AP_Notify
AP_HAL_PX4: compile error fix
Copter: integrate Toshiba_LED_PX4
Toshiba_LED_PX4: local #defines for led brightness
Plane: integrate AP_Notify
Copter: re-order #defines of AP_Notify
Rover: integrate AP_Notify
AP_Notify: simplify interface to avoid timers and external calls

this changes AP_Notify to use updates via notify.update() at 50Hz,
avoiding the need for the 1kHz timer. It also creates a parent class
for ToshibaLED so that the I2C and PX4 ToshibaLED drivers can be
abstracted out.

Pair-Programmed-With: Randy Mackay <rmackay9@yahoo.com>
AP_InertialSensor: update for new notify API
AP_GPS: don't need notify.h here
Plane: updates for new notify API
Copter: updates for new notify API
Rover: updates for new notify API
Copter: fixed build with AP_AHRS changes
Rover: fixed build with AP_AHRS changes
VARTest: fix build for AP_Notify changes
GCS_MAVLink: added missing header
AP_Notify: added missing files
AP_Notify: enable board LEDs for ESC calibration

Pair-Programmed-With: Randy Mackay <rmackay9@yahoo.com>
Copter: added a delay in ESC calibration

this allows AP_Notify to run via the delay callback