Merge pull request #1145 from Bart39/dev

added a.b.music to Category byGroup()
Username check, PHP 5.3 compatible install, SAB Url & API Key check
updated Username check, PHP 5.3 compatible install, SAB Url & API Key check
clean up
changed book cover view so that books are grouped by bookinfoid (similar concept to movie cover view)
 fixed book order by clause for author