Copter: BugFix DO_SET_ROI returns Lat,Lon,Alt to GCS
TradHeli: Fix for yaw offset switching.  Yaw Offset should switch on and off with the main motor, not waiting until the rotor has reached full speed.
HAL_PX4: fixed build for new PX4Firmware
AP_HAL: support uartD on some boards

PX4 and SITL get an extra UART
HAL_AVR: added NULL uartD
HAL_SITL: added uartD
HAL_EMPTY: added uartD
HAL_FLYMAPLE: added uartD
HAL_LINUX: added uartD
HAL_PX4: added uartD
GCS_MAVLink: added support for 3 UARTs

support 3 UARTs on non-AVR platforms
Copter: added uartD support

this also brings GCS_Mavlink.pde closer to the plane implementation
Copter: removed extra features of copter telemetry merge
Copter: added SERIAL2_BAUD and rename SERIAL3_BAUD to SERIAL1_BAUD
PX4: enable uartD by default in rc.APM