Support deleted album messages in one time?

[Gowee]

Now an album message has to be deleted with multiple commands.

In general, most such messages are spams to deleted shortly after being posted. I propose storing a small number of recent messages in memory for each group, and linking all messages somehow within an album when processing deletion commands. The approach shouldn't bring much maintenance burden, since it does not touch the DB.

If this sounds reasonable, I'd be happy to submit a PR.