Full E-flite Convergence support

… sorry, it works still perfect on 1.8.0 Final release with mixer.h line 42 changed to 330 (compiled with GCC 7.2.1)

1.11.x mixer.h needs to be changed to 430 and the extended mixer has to be loaded later by adding a line in /microsd/etc/extras.txt.
Loading it automatically while the start procedure could completely block Spektrum rc functionality.
Vectored thrust in FW works but currently the rear engine doesnΒ΄t switch off MC control using PixRacer or any other fc in FMU only mode.
Attention since PX4 V1.10 the sign of all Aileron sources must be reversed in all displayed mixers above!

Archiving as stale