Log Message:
Update dbmail to 2.2.12.

Changes since 2.2.11:

    * Backport IPv6 support
    * Remove generated autoconf files from the release. Please install
automake-1.9 and run autoreconf -i before running configure
    * Backport the fix for duplicate mailboxes in LIST/LSUB responses
    * Backport for internaldate as UTC
    * Fix for file descriptor leakage

Bugs fixed since 2.2.10:

0000742: [Authentication layer] PATCH: authldap.c - multiple attributes
         for field_mail (Toast) - resolved.
0000731: [Documentation] Missing documentation of database layer logging
         control (paul) - resolved.
0000723: [Database layer] simultaneous mailbox creation (paul) -
         resolved.
0000709: [Database layer] Some sql optimizations (paul) - resolved.
0000721: [Authentication layer] mail quota in ldap not used during
         delivery (paul) - resolved.
0000698: [IMAP daemon] PostgreSQL 8.3.1 can't execute query (paul) -
         resolved.
0000712: [General] traces to stderr may cause core dumps if hostname
         >=16 (paul) - resolved.
0000710: [IMAP daemon] eliminate annoying "[Illegal seek] on
         read-stream" message from imap4d - resolved.
0000704: [IMAP daemon] IMAP TEXT searches stop at headers - resolved.
0000670: [IMAP daemon] IMAP TEXT searches only seem to search headers
         (paul) - resolved.