Removed unnecessary Control Object() use
added connectValueChanged to ControlObjectThread
Introduced ControlObjectSlave a successor of ControlObjectThread.
ControlObjectSlave connects only on demand and has no "From this
signal". Because connect is a static Qt funtion it might be to risky to
remove ControlObjectThread yet. ControlObjectSlave should be used in new
code.
Added default constructor, Connect to ControlObjectPrivate only if
required.
changed EnigineBuffer::m_pSampleRate to ControObjectSlave
changed addition COs to COSs in ClockControl and BpmControl
store pointer to creating CO in CDP
Removed separate Hash table from ControlObject.
Merge branch 'master' into atomic-co2
Introduce QSharedPointer for ControlDoublePrivate
Fix double add to hashtable
Delete all leaking cdp one shutdown
Changed some ControlObjectThreadMain instances to ControlObjectThread if
no direct connection is used.
Changed some more ControlObjectThreadMain instances to
ControlObjectThread if no direct connection is used.
Finaly Changed remaining ControlObjectThreadMain instances to
ControlObjectThread where no direct connection is used.
Merge branch 'master' into atomic-co
Merge branch 'master' into atomic-co2

Conflicts:
	src/control/control.cpp
	src/control/control.h
Merge branch 'master' into atomic-co3
call select() by changed signalfrom PlaylistDAO to have PlaylistTableModel always up to date. Fixes https://bugs.launchpad.net/mixxx/+bug/1213603
Fixed drag and drop position and removed duplicated code, fixes https://bugs.launchpad.net/mixxx/+bug/1213734