Some early gdb/Python macros for working with NuttX.

Note; only tested with gdb 7.6. Will definitely not work with the stock PX4 toolchain's gdb.
Add ioctl to find out if mag is external or onboard
Sensors should now take into account the orientation of an external mag
Merged master
Better transparency in IO mode display, fixes to commander arming, minimum publishing rate for arming
Make a distinctive sound when the IO start fails (e.g. due to version mismatch)
Put console and syslog on UART8, added support to nshterm for proper serial port config
vehicle_local_position topic updated, position_estimator_inav and commander fixes, only altitude estimate required for SETBELT now.
Merge branch 'fmuv2_bringup_new_state_machine_drton' of https://github.com/cvg/Firmware_Private into fmuv2_bringup_new_state_machine_drton
vehicle_control_mode.flag_armed added, reset integrals in multirotor_att_control when disarmed
multirotor_pos_control: reset integrals when disarmed
Merge branch 'fmuv2_bringup' of github.com:cvg/Firmware_Private into fmuv2_bringup_new_state_machine_drton
merged
Fixed merge compile errors
Minimized nshterm flags, fixed some pretty stupid non-standard coding in top, now behaving with two shell instances as expected
Fixed status changed flag
Minimized nshterm flags, fixed some pretty stupid non-standard coding in top, now behaving with two shell instances as expected
Merge branch 'fmuv2_bringup' into fmuv2_bringup_new_state_machine_drton
Added stop command to RGB led
Corrected orientation of external mag