Refactor BlaPlaylist's `set_row' method

Signed-off-by: Niklas Koep <niklas.koep@gmail.com>
Move BlaQueue class to its own source file

Signed-off-by: Niklas Koep <niklas.koep@gmail.com>
Factor out common playlist and queue code

Signed-off-by: Niklas Koep <niklas.koep@gmail.com>
Defer view initializations

Signed-off-by: Niklas Koep <niklas.koep@gmail.com>
Add detail label to the "Clear" menu item

Signed-off-by: Niklas Koep <niklas.koep@gmail.com>
Treat BlaQueue class as singleton

Signed-off-by: Niklas Koep <niklas.koep@gmail.com>
Use BlaPlaylistManager as singleton

Signed-off-by: Niklas Koep <niklas.koep@gmail.com>
Refactor library initialization

Signed-off-by: Niklas Koep <niklas.koep@gmail.com>
Remove `return_track' kwarg from BlaLibrary's ...

`update_track' method

Signed-off-by: Niklas Koep <niklas.koep@gmail.com>
Refresh playlist rows on `library_updated' signals

Signed-off-by: Niklas Koep <niklas.koep@gmail.com>
Move BlaProgress from bladb.py to blaguiutils.py

Signed-off-by: Niklas Koep <niklas.koep@gmail.com>
Refresh window title on `library_updated' signals

Signed-off-by: Niklas Koep <niklas.koep@gmail.com>