Added a worker fragment to update reader tags, avoids problems caused by device rotation
Renamed ReaderTaskFragment to ReaderOneShotTaskFragment to better describe its purpose.
Task fragment is now removed on signout so tag update happens again after login
Merge branch 'hotfix/3.0.2' into issue/1706-illegalstateexception-readerpostlist-round2
Merge branch 'issue/preparing-3.0.2-beta-3' into issue/1706-illegalstateexception-readerpostlist-round2
Merge branch 'issue/1706-illegalstateexception-readerpostlist-round2' into hotfix/3.0.2