Add catchall subcommands to manpages

Include catch-all count in domaininfo output

Make PL/pgSQL function feed back identity for mailboxes/relocated when there are catchall destinations. Without catchall aliases, if no virtual_alias matches, the query can just return NULL and Postfix will later check mailboxes/relocated for the address to rewrite. However, since virtual aliases are handled long before mailboxes/relocated, a catchall alias would also catch mail to mailboxes and relocated addresses, which we do not want. The way to tell postfix to keep delivering is for the virtual alias map to return the search key itself (identity function). This patch changes the postfix_virtual_alias_maps Pl/pgSQL function to do exactly that, but only if there are catchall destinations defined for the domain in question — otherwise it returns NULL when no match is found.

Fix syntax errors

Modify virtual_alias_maps function to check mailboxes/relocated first

Make virtual_alias_maps function search catchall when no aliases are found

Add catchall info to domain_info output

Correct syntax errors

Fixup catchall_info to return iterator, not self

Correct syntax errors

Teach CLI about catchall* commands

Provide catchall_* methods to the Handler class

First version of a CatchallAlias class I based the CatchallAlias class in catchall.py heavily on the Alias class, but by copy, not deriving. The two are functionally related, but the implementations are too different because CatchallAliases have no localpart.

Add database table for catchall destinations Catch-all aliases are stored for a domain. Since there can be multiple destinations per domain, this is done using a 1:n relation on the gid. This commit extends the SQL schema definition and also provides appropriate upgrade DDL.