AP_HAL_SMACCM: fix to goofed PPM_MAX_CHANNELS macro
Copter: improved 'FRAME' docs
AP_Motors: fixed setup of ESC update speeds
HAL_AVR: switched to 8 bit mask

max buffer size is now 256. This makes serial faster
HAL_SMACCM: fixed build warning
AP_Baro: only build BMP085 driver on APM1
AP_InertialSensor: only build Oilpan driver on APM1
AP_GPS: put SIRF init_messages in progmem

this saves 32 bytes of memory
MAVLink: moved CRC table into program

this saves 256 bytes of memory
AP_HAL_SMACCM: Panic if taking a semaphore held by current thread.

- Catches bugs with attempted recursive semaphore taking.
Arduino.mk: default config.mk port changed to ACM0 (for APM2)
AP_HAL_SMACCM: Semaphores fixup
AP_HAL: add Scheduler methods in_timerprocess, system_initialize
AP_HAL_AVR: Implement new scheduler methods
AP_HAL_AVR_SITL: Implement new Scheduler methods
AP_HAL_Empty: Stub out new Scheduler methods
AP_InertialSensor_MPU6000: fix sync/async semaphore usage with new scheduler
AP_HAL_SMACCM: Implement new scheduler methods.

- Set the system initialized after call to "setup" in main.
AP_Baro_MS5611: Don't panic if taking semaphore fails during init.

- The MPU6000 holds on to the I2C semaphore for quite some time during
  init, which caused a panic when the MS5611 is also on I2C.
AP_HAL_AVR: main calls system_initialized