Fix close on crash patch which was  posted on the mailing list by Filipe Coelho
Merge pull request #558 from diizy/fixclosecrash

Fix close on crash patch which was  posted on the mailing list by Filipe...
SampleBuffer: fix a segfault when moving a loop point while playing a note, also do some sptring cleanup (some unused/redundant variables removed)
Also, some codepath optimization: add a method to SampleBuffer for setting all loop/start/endpoints at once, so we don't have to wait for mutex unlocks 4 times in a row. Then make AFP utilize this method.
Merge pull request #559 from diizy/loops

SampleBuffer: fix a segfault when moving a loop point while playing a no...
moved fastPow() to lmms_math.h
Merge pull request #565 from grejppi/master

move fastPow() to lmms_math.h
Merge pull request #564 from diizy/master

Optimize linear interpolation function
Track: make the song editor background CSS-stylable with qproperties
TCOView: Make patternviews foreground elements stylable with qproperties
For consistency, define text colour of bb-tracks in CSS too
Monstro updates: fixes, improvements, optimizations