Add Kalman filter class
This isn't working properly -- the tests pass, but only because I've
set the tolerance high. The errors are implausibly regular, as discussed
in the notes at the top of kalman.cpp.
The interface is reasonable, though, so it'll do for the moment.
Change Kalman filter implementation to have speeds as fraction of full, and angles as radians.
This matches activities.cpp's requirements better (and makes more sense, really --
this is not where this scaling complication should be).
The large error is still there, though.
Integrated into qp.ino
Addresses issue #5 (but not resolved until it's been tested with the telescope)
This appears to be working.
This finally seems to have the right number of clicks-per-degree.
The Kalman filters look plausible (so closes issue #5)
There are some spurious errors: !Activity::delete: double free n=0 mask=0x0
Currently all fault detection is disabled.