moving single segments on empty level
always update level when setcurMouseSegment is set
deleting to empty level
deleting to empty level -> undo
delete first and last segment boundary
delete and insert segments on empty level

still need to fix strange epgdorsal error
strange epgdorsal error fixed !
rename errror
spectro correction
Merge branch 'master' into empty-levels
Merge branch 'empty-levels'
Merge branch 'master' into preEmphasis
now using strict mode
single pass of fft+draw and doc update
back 2 double loop again (4 got scaling problem)
calculating preemphasis
Merge branch 'Point-Correction' Fixes #38
first test on history service with mocked data

todo: updateCurChangeObj with SSFF
and more applyChange besides moveBoundary & renameLabel
move elements without neighbors fix
conv filter preemph added