Support for 5-star-ratings & bugfixes

Hi,

this pull request contains 3 commits. The first adds support for 5-star-ratings. I think this is related to https://github.com/JaredSartin/Better-Music-Beta/issues/11.
The other two commits fix some bugs (I do not know the exact consequences of the "fix for setting of current playing status" bug, but this is obviously a copy&paste-mistake).

Best regards,
Sven