StatusStorage::SQLite: add spec about vaccum.
StatusStorage::SQLite: implement put_statuses() (not tested)
Add t/StatusStorage_SQLite. It's just a reminder.
StatusStorage::SQLite: implement get_statuses().
StatusStorage::SQLite: now it does not call 'goto' in try{} block. I think this is safer.
StatusStorage::SQLite: _get_timeline_id() now returns undef if there is no timeline for the given name. put_statuses() now creates a timeline entry if not exists.
StatusStorage::SQLite: implement ack_statuses(). Some bound variables for SQL conditions are explicitly stringified because they might be a reference.
StatusStorage::SQLite: implement delete_statuses().
StatusStorage::SQLite: implement get_unacked_counts().
Test::StatusStorage: fix POD: $loop and $unloop are optional.
StatusStorage::SQLite: fix some minor errors. statuses tables are updated with table contraint for PRIMARY KEY (timeline_id, id).