The correct determination of Windowed mode is critical to
   maximise the speed on a USB based upload.

   This commit bases the detection of a Serial (FTDI) on the
   fact a CDC ACM port (USB) does not really have a baud rate.
   We bump the baud rate to 233% of the requested baud rate to
   see if the SYNC is acked. If it is Acked it must be a USB
   port and Windowed mode is turned off. This removes unnessary
   baud rate based delays from the proframing logic. If it is a
   real Serial port getSync will not get the ACK and Windowed
   mode is turned on.

When a gyro driver is stopped, the topic is unadvertised and
orb_group_count() returns a smaller count. This can have the effect, that
we poll on a certain gyro fd, but since _gyro.subscription_count is reduced
we never do the orb_copy for that fd.

This cannot happen when armed. And only someone playing with the shell
can trigger it (sensor failures do not have that effect).

This makes sure that poll() never returns immediately.
accel & mag are only updated to keep the code in sync.

Should some of these be of interest to someone, we should create a profile.

Copy/paste logic in rc.interface to group MIXER and MIXER_AUX logic, alphabetize hardware list in rc.interface, alphabetize set/unset lists in rcS, and add -p argument to pwm failsafe calls per issue #9775.

Group instances of UAVCAN logic into a single block and copy/paste/regroup OUTPUT_MODE logic to form on block of code handling OUTPUT_MODE.

   FMUv5 has singlewire support