Revert "emit signal when list of displayed rows change"

This reverts commit f7bbb35b35adff30c22ac65de81f1db311778c87.

Conflicts:

	src/library/library.cpp
	src/library/library.h
	src/widget/wlibrarytableview.h
Do not create new filters in setFilters(). Update previously created filters instead.
Change the sample rate in setFrequencyCorners(). If frequency corners are changed, do ramping in the next process() call
Pass the sample rate to setFrequencyCorners()
Use memset and memcpy for copying and initializing buffers
Rename EqEffect to EQDefault
Rename EQ knobs to LOW, MID and HIGH
Add descriptions to Default EQ and remove redundant includes
building tio from location instead get it through the tablemodel

tablemodel->getTrack(index) was implemented to be called when user select a track to play, it is a virtual method which will do a lot of heavy things that won't be useful for coverArt stuff.
coverartcache - using util/singleton.h
cache cover location in tableview
add the coverlocation in the temporaryview of the database. With
this we can avoid having to do db queries when 'loadCoverArt' is emitted
from a tableview. (thanks kain88)
Attempt at switch type parameters
Initial refactoring - loading covers from coverLocation and trackId instead of using TIO.

Using TIO requeries a lot of unnecessary information for coverart stuff
and it can make the loading/searching process slower when the user
request a lot of pixmaps at the same time.
Using pixmapFound(int trackId, QPixmap cover) instead of pixmapFound(QString coverLocation, QPixmap cover)
Moving TIO::parseCoverArt() to coverart class
Removing get/set coverartlocation from TIO
Moving all coverart class to coverartdao
it also remove the coverart class
Update the underlying EffectParameter separately for each type of parameter
Hashing list of running covers by QSet<int> instead of using QStringList
Fix typo in computing m_maximum