use common-config collection names instead of hardcoded values

Signed-off-by: Tomas Neme <lacrymology@gmail.com>
save new sticky messages in the db and delete them when clear

Signed-off-by: Tomas Neme <lacrymology@gmail.com>
use message model instead of hardcoded object

Signed-off-by: Tomas Neme <lacrymology@gmail.com>
export error codes constants for ease of use

Signed-off-by: Tomas Neme <lacrymology@gmail.com>
send message on outOfSync

Signed-off-by: Tomas Neme <lacrymology@gmail.com>