Cleanup events no longer used

Some event id:s isn't used anymore, but since removing event types in
favor for callbacks, we could simply remove them, to clean up for
future refactoring

Signed-off-by: Max Sikstrom <msikstrom@op5.com>
Comments: Remove expired feature and events

As a part of cleaning up the events, it was discovered that the comment
expiration feature wasn't working at all, and never actually tried to
be used.

Instead of fixing the not used internal functionality, the not used
internal functionality can instead be removed, and one more event type
is gone.

Signed-off-by: Max Sikstrom <msikstrom@op5.com>