to make it non-blocking and ommit opening the same
named pipe multiple times inside the same process
which seems to be not supported in cygwin.

Updated rc.vtol_defaults to correct PWM_AUX behavior for VTOL airframes. Added PWM_AUX_RATE to rc.vtol_default and set parameters directly instead of environment variables.

hash check and heartbeat forwarding

- hash check disabling: for systems where a companion link forwards messages
to QGC (e.g. via LTE) parameter streaming will be stopped as soon as QGC
sends the request to stop the stream. If the companion side for some reason
still requires the stream to be active we need to disable QGC from stopping
the stream. Normally dronekit should be responsible for filtering out the
request from QGC but apparently this is not possible.

- disable heartbeat forwarding: dronekit does seem to get confused if
heartbeats from another system other than the autopilot get forwarded to it.
Example: Sending messages from QGC via the autopilot to dronekit running on
companion computer.

Signed-off-by: Roman <bapstroman@gmail.com>