px_uploader:Platform and Timming indepentant Serial detection
px_uploader:Platform and Timming indepentant Serial detection

   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.

acfloria/Firmware,Aerotenna/Firmware,mje-nz/PX4-Firmware,dagar/Firmware,PX4/Firmware,krbeverx/Firmware,PX4/Firmware,krbeverx/Firmware,Aerotenna/Firmware,mje-nz/PX4-Firmware,krbeverx/Firmware,Aerotenna/Firmware,Aerotenna/Firmware,acfloria/Firmware,dagar/Firmware,acfloria/Firmware,acfloria/Firmware,acfloria/Firmware,dagar/Firmware,acfloria/Firmware,PX4/Firmware,krbeverx/Firmware,dagar/Firmware,dagar/Firmware,dagar/Firmware,krbeverx/Firmware,Aerotenna/Firmware,PX4/Firmware,mje-nz/PX4-Firmware,acfloria/Firmware,Aerotenna/Firmware,PX4/Firmware,mje-nz/PX4-Firmware,krbeverx/Firmware,PX4/Firmware,Aerotenna/Firmware,dagar/Firmware,krbeverx/Firmware,mje-nz/PX4-Firmware,mje-nz/PX4-Firmware,PX4/Firmware,mje-nz/PX4-Firmware