Idea: make sorting and assigning by rating easier

[fossfreedom]

from issue #24

Look at an album rating idea as well as individual track level.

Since RB doesnt support album ratings - this will probably just set the rating for all tracks in the album.

Also look more closely at the setting of ratings.

Possibly if using a separate pane then we can use the standard RB Rating object that offers stars allowing to click directly.

EDIT - think we should use the RB.Rating widget on the tracks pane (at the bottom of the screen) - clicking a start changes all tracks for that album(s). If multiple albums selected, RB.Rating should still average all tracks for all albums

An optional sort by Rating - similar to the option sort by year would be useful as well.

[fossfreedom]

damn - also need to update the rating stars depending upon which entry track is selected - should work the same as album selection

i.e. select one track - stars rating updated. Select multiple tracks, stars rating should be set to zero.