HPWM + Remove VCTRL + Add AltiHoldState + MWRate to OSD

[fujin]

This is a combination branch of all of my previous pull-requests to enable/fix HPWM for Brain, pretty much the following:

• HPWM for brain #18
• Remove vctrl on HPWM #19
• Add AltitudeHoldState on HPWM branch #20
• Add MWRate to osd #22

Refs upstream branch

[BrainFPV]

See #18