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'