implement cacheStatusManager and subscriptions
fix PHP docblocks
update copyright header in backend classes
update copyright header for backgroundjob
fix some businesslayer issues
cleanup appinfo
controller cleanups
db cleanups
remove unused classes
fix backend utility class
some di cleanups
some timezone api fixes
some fixes for Db collection
fix var name
add public interfaces
php docfixes for db backend
a few businesslayer cleanups
add todo for me
controller cleanups
implement public interfaces for internal db classes