Fix legacy C. Pass -Wall -W -Wmissing-declarations -Wwrite-strings on
gcc45.

   - avoid implicit int, declare void functions void
   - return values from non-void functions
   - put most external declarations properly in header files
   - use some static and const
   - fix up a big mess with function pointer casting
   - use standard includes, don't provide own decls of standard functions
   - use types matching libc when providing own malloc, printf, and putchar
   - use <ctype.h> functions correctly
   - silence assorted compiler warnings
   - fix some bugs exposed by compiler warnings
   - don't intentionally exercise signed overflow
   - remove some unused items
   - add patch comments to other patch (patch-aa)

As this includes several fixes and removes some undefined behavior on
a commonly reachable code path, bump PKGREVISION.
Stuff from the past few days.
Update squirrelmail to 1.4.23pre14345, snap shot from squirrelmail's
repository.  Approved by wiz@.

* Now work well with PHP 5.4 and later.

Version 1.4.23 - SVN
--------------------
  - Added capability to issue SEARCH commands in literal format (so that
    non-ASCII search terms are handled RFC-correctly).
  - Fixed hook name clash: new "smtp_auth" hook added in version 1.4.22
    has been renamed to "smtp_authenticate"
  - Added SASL PLAIN mechanism for IMAP logins; backported from version
    1.5.2.
  - Prevent syslog warning in call_user_func_array() call when no
    arguments given.  Patch from Jean-Philippe Guerard (#3309935).
  - Changed the read_body_menu_top hook from concat_hook_function to
    do_hook_function (plugin authors please note)
  - Always ensure that the Reply-To header is a full email address in
    outgoing messages
  - Fixed issue with Noselect mailboxes being clickable in folder list
  - Made performance improvements in mailbox listing
  - Attachment filename extensions changed from ".msg" to ".eml"
  - Unified address book searches somewhat: file-backed address books now
    search in each field individually; database-backed address books now
    search in fields other than first/last name (nickname, email); LDAP-
    backed address books now search in common name fields as well as by
    email address (cn, sn, givenname, mail)
  - You may now enable LDAP-backed address books to be listed (using
    the "List all" button on the address search screen accessed via
    the "Addresses" button on the compose screen) by adding
    "$ldap_abook_allow_listing = TRUE;" (without quotes) to
    config/config_local.php (previously, this required editing of a
    file).
  - Added ability to control browser rendering mode (quirks versus
    standards) - see the $browser_rendering_mode setting in
    config/config.php or the "4. General Options ==> 19. Browser
    rendering mode" setting in the configuration tool (#3240356).
  - Added "search_index_before" hook (analog of the "mailbox_index_before"
    hook)
  - Made performance improvements in security token handling
  - Improvements for compatibility with PHP 5.4.
  - Added option that allows users to have replies to their own
    messages sent to the recipient of the previous message (#3520988).
Note update of mail/squirrelmail package to 1.4.23pre14345.
sendmail is incompatible with current versions of databases/db4
as the latter is now threaded, so delete the option