Added check if sqlite driver avaiable
Improved usage of getTrack.

getTrack must be usef only from TrackCollection thread.
removed src/library/dao/threaddao.cpp src/library/dao/threaddao.h
Improvements according to code review 4-5.
Work in progress.

Rewrite according Daniels 4-5 review.
Rewrited all onShow.
Avoioded deadlock w/ BaseTrackCache
Probably improved bug w/ deadlock.
Needs more checks.
Corrected all warnings from Daniels review 6.
Little changes according Daniels warnings.
Changes to external features
Improved LibraryScanner.

Leaved itunesfeature as it was.
Fixed issue with locking UI. Added protection to m_trackInfo.
Changed connection type for TrackDao in MixxxLibraryFeature.
Merge branch 'master' into LibraryConcurencyRefactoring
Changes according to Daniels 7th review.
Fixed BaseSqlTableModel::getTrack
added gain knob and a basic LED mapping
include saved build falgs from custom.py in branch virtualization
Code style fixes in EngineMaster
Add Hercules Mk4 Support, fixes https://bugs.launchpad.net/mixxx/+bug/1213752