Prevent duplicate connections to the underlying ControlObjectPrivate if connectValueChanged() is called multiple times on a ControlObjectSlave.
Get rid of another cached value -- they are nothing but trouble!
Fix connection type argument in ControlObjectSlave.
Header/include cleanups across the codebase.

* Eliminate all instances of including QtCore, QtGui, or QtXml.
* Replace all old-style Qt header inclusions with new-style (e.g. #include <application.h>).
* Include QtDebug instead of QDebug.
* Update many classes to include the Qt classes they use in their header and implementation file.

This speeds up compile and link performance and reduces the size of the compiled object files. My build directory dropped by 50MB.
Strip unnecessary parentheses if only one search clause is present. Update test expected output to expect album_artist filter in addition to artist filter.
Merge remote-tracking branch 'mixxx/master' into master_sync

Conflicts:
	src/engine/ratecontrol.cpp
Need QLibrary for two files under linux.
Merge remote-tracking branch 'mixxx/master' into master_sync
Disable master mode if reaching end of track to prevent everything from stopping.
Fix braindead type and if() error, fix test to check for it.
Also fix testing infrastructure so it reports a fake but plausible playposition.
Merge pull request #96 from mixxxdj/waveform-dejerk

Waveform dejerk: visualPlayPos + SyncThread + waveform refactoring
Merge branch 'master' into features_key

Conflicts:
	build/depends.py
	src/audiotagger.cpp
	src/basetrackplayer.cpp
	src/basetrackplayer.h
	src/dlgpreferences.cpp
	src/dlgpreferences.h
	src/engine/enginebuffer.cpp
	src/engine/enginebuffer.h
	src/engine/enginebufferscalelinear.cpp
	src/engine/enginebufferscalest.cpp
	src/library/cratetablemodel.cpp
	src/library/dao/trackdao.cpp
	src/library/librarytablemodel.cpp
	src/trackinfoobject.cpp
Merge branch 'master' into features_key

Conflicts:
	src/engine/enginebuffer.h
Merge remote-tracking branch 'origin/master' into master_sync

Conflicts:
	src/engine/bpmcontrol.cpp
	src/engine/enginebuffer.cpp
Move include to fix compilation failure on linux
Merge branch 'master' into master_sync
Fixed building with ffmpeg, a regression from 4845e95acb542120191f309e050d785699730048
Don't store a pointer to PA TimeInfo.
Clean up includes of cmdlineargs.h.
Merge branch 'master' into master_sync