Merge pull request #1 from dbaarda/tidy/ewma2

Tidy/ewma2
High-frequency timer does nothing with sleep interval, it turns out
Don't assume or use 1ms interval, on Windows it gets rounded to 15.6 ms anyway
Simplify Accela's UI and preset equations
Revert "High-frequency timer does nothing with sleep interval, it turns out"

This reverts commit c6e5a5f449f95a833b826ebfae870a2e519fcfa0.

Actually, it does for Sleep(x) where x > 1 and x < 15, but only for Windows newer than XP.

Next time let's check for ourselves instead of using obsolete info from the 'net...
Undo the filtering clusterfuck following discussion with dbaarda
Workaround camera frame-retrieval badness
UI cleanup, tracking overlay already provides that information. Expose one internal value less.
Remove dead code
Allow for changing keyboard shortcuts while the tracker is running
Cleanup unused functions
Reorder side effects to avoid use-after-free
Allow for editing filter settings while the software is running
Make Accela dialog non-modal
Remove per-file version history. Be careful not to touch copyright information.
Reduce copy-pasted code during dynamic library load
Remove copypasta entirely in shared object loading
Fix include guard
Correct Accela Mk3 default coefficients
Don't expose filter internal state. Sprinkle some const