Add option to disable compass

[xandro0777]

Hi, I would like to have that because constant use of the compass sensor drains some battery (compass sensor for physical reasons requires a considerable electric current) and apparently (own observation on 2 devices) significantly impairs GPS reading. Although this is difficult to benchmark my devices typically need considerably longer to get a GPS fix when the compass is on.

There are many devices without compass which apparently also work with OsmAnd so making the compass configurable should not cause any problems?

[vshcherb]

• Compass on the map is not used when set position to North.
• Compass is also used when map is synchronized with location.

Compass could not be disabled for now.

[nekohayo]

It would also be needed for devices where the compass and/or magnometer are not physically present, or somehow broken. In that case, disabling those should make OSMAnd rely only on GPS positioning, including for map orientation, navigation, etc.

[jasom]

In addition to the other reasons given, I most often use my phone for navigation in a magnetic mount; needless to say the compass is worse than useless in such a situation.