AP_Compass: move param to table per instance

[IamPete1]

I was looking at changing COMPASS_MOTCT for battery instances and decided that the whole compass param tree is a mess. So I have converted to a per instance table.

The names have changes a little since the number has to come before the suffix.

COMPASS_ORIENT changed to COMPASS1_ORIENT
COMPASS_ORIENT2 changed to COMPASS2_ORIENT
ect....

Will need some GCS change to look for the new param names, I do think the naming is a improvement. COMPASS1_ now gets you all compass 1 params rather than having to try and pick them out of the list maunaly.

COMPASS_ENABLE has also been moved to the top of the table and been given a enable flag.

Once this is in I would like to move COMPASS_MOTCT to the new instance param so we can compensate different compasses for different things.

[IamPete1]

This one actually does save flash,

Binary           text             data         bss            total
---------------  ---------------  -----------  -------------  ---------------
arduplane        -104 (-0.0107%)  0 (0.0000%)  0 (0.0000%)    -104 (-0.0095%)
antennatracker   -112 (-0.0171%)  0 (0.0000%)  0 (0.0000%)    -112 (-0.0142%)
arducopter-heli  -92 (-0.0100%)   0 (0.0000%)  4 (+0.0031%)   -88 (-0.0084%)
arducopter       -72 (-0.0077%)   0 (0.0000%)  0 (0.0000%)    -72 (-0.0068%)
ardurover        -80 (-0.0096%)   0 (0.0000%)  0 (0.0000%)    -80 (-0.0083%)
blimp            -96 (-0.0142%)   0 (0.0000%)  0 (0.0000%)    -96 (-0.0119%)
ardusub          -100 (-0.0125%)  0 (0.0000%)  -4 (-0.0031%)  -104 (-0.0111%)

[IamPete1]

I should probably add back the param descriptions for the old param names.

[peterbarker]

Need @rmackay9 to weigh in here (and maybe @meee1 )

This is going to cause a great deal of issues for MissionPlanner - dependence on current parameter names.

May also cause issues with the priority table if we take this opportunity to move from COMPASS_*1 to MAG1_

[rmackay9]

I like the change so I've approved it but I worry we will regret the impact on users.

Let's see what @meee1 says about the required MP changes before we merge this.

[IamPete1]

@meee1 How much effort is it for mission planner to deal with these changes?

[tridge]

need to ask @meee1 to do the MissionPlanner changes before we merge this. Also need to test with QGC. I think we should also check with UGCS

[IamPete1]

Mission Planner Beta now supports this. QGCs does not, but these are the options we have:

Since it does not do priority and ordering at all I don't think it really makes any difference.

[tridge]

i'll wait for @rmackay9 to be on a dev call for final decision

[rmackay9]

Sorry I missed the call, it's a bit borderline but I"m ok with merging this.