Rating improvements

[kelsos]

From @Snaptags on August 26, 2017 10:57

I'd suggest these improvements to track rating:

• add a setting to disable "half star" ratings. MusicBee has such a setting to force ratings to be integers.
• display the current track rating in the title bar
• after setting/changing a rating auto-close the "Rate the playing track" dialoge

Copied from original issue: kelsos/mbrc-plugin#38

[kelsos]

@Snaptags I moved this issue here since it regards the Android application functionality and not the plugin.