Move connections to c-tor in MainExecuter, allow using MainExecuter from main thread.
call MainExecuter::getInstance().call() in TrackCollection::callSync()
removed missleading debug messages. Use a reference of MainExecuter.
Merge remote-tracking branch 'daniel/LibraryConcurencyRefactoring' into
LibraryConcurencyRefactoring
Added possibility to stop thread TrackCollectioin.