Remove unnecessary and faulty new_frame detection.

This would only detect a non-new-frame when the camera input equalled
the filtered output, which would only happen after a long period of no
movement or noise. It also is not recommended for this type of filter.
Simplify first_run handling to only initialize filter states.
Make reset() set first_run=true;
Update filter constants for dt=3ms as used in tracker.cpp.

Change expressions and comments to make it easy to change dt.
Change noise filtering from 2mins to 60secs.
Merge pull request #81 from dbaarda/dev/kalman

Dev/kalman -- Let it rip!
add-comment
rotation below -99 didn't display, just froze
drop decimal places for rot/trans in UI
nonsense
submit mapped data to filter, not raw
gcc too much a piece of work often

Issue: #81
Rename alpha/smoothing/output vars/attrs with better names.
Simplify EWMA2 licence and add filter description comment.
Merge pull request #83 from dbaarda/dev/ewma2

Dev/ewma2
add ui layouts for legibility's sake
show exact slider value in now-read-only spinboxes.
default to 1:1 lienar mapping

Issue: #46
No time to implement a kitchen sink

Issue: #65
don't reduce usleep at ms granularity pointlessly
Merge commit 'f78b96a' into unstable

* commit 'f78b96a':
  gcc too much a piece of work often
  submit mapped data to filter, not raw
  nonsense
  drop decimal places for rot/trans in UI
  rotation below -99 didn't display, just froze
  add-comment