Make Juk mpris2 metadata closer match vlc / dragon / amarok metadata with empty fields
Review Request #121731 - Created Dec. 28, 2014 and submitted
Juk behaviour with empty metadata fields was to include the field irregardless of whether it was empty or not. This patch follows vlc, dragon, and amarok behaviour which is to just omit the field when there is no information.
Compile, run. Test with files with appropriate metadata characteristics.