Update to 6.5.6. From the changelog:

* Fix IDLE mode regression (it didn't worked) introduced
  after v6.5.5 (pointy hat goes to Eygene Ryabinkin, kudos --
  to Tomasz Żok)
* Add knob to invoke folderfilter dynamically on each sync (GitHub#73)
* Add knob to apply compression to IMAP connections (Abdó Roig-Maranges)
* Add knob to filter some headers before uploading message
  to IMAP server (Abdó Roig-Maranges)
* Allow to sync GMail labels and implement GmailMaildir repository that
  adds mechanics to change message labels (Abdó Roig-Maranges)
* Allow to migrate status data across differend backends
  (Abdó Roig-Maranges)
* Support XDG Base Directory Specification
  (if $XDG_CONFIG_HOME/offlineimap/config exists, use it as the
  default configuration path; ~/.offlineimaprc is still tried after
  XDG location) (GitHub#32)
* Allow multiple certificate fingerprints to be specified inside
  'cert_fingerprint'
Updated mail/offlineimap to 6.5.6
0.997a (23 Jul 2013)

 - minor fixes/changes in packaging, no code changes.
   In particular, fixes a build failure on *BSD introduced in 0.997

0.997 (29 Jun 2013)

 - main feature of this version is ipv6 support.  Many thanks to
   Geoffrey T. Dairiki for the implementation of btrie (btrie.c) which
   is far superior to old ip4trie code and handles both v4 and v6

 - feature: ip6trie - new dataset supports listing of arbitrary length
   ip6 CIDRs, along with individual A/TXT values for each prefix

 - feature: ip6tset - new dataset supports listing of ip6 /64 subnets
   and the exclusion of /128 subnets; only supports a single A/TXT value
   for the entire dataset

 - optimization: ip4trie - using new trie implementation (developed for
   the ip6trie dataset) decreases memory consumption by roughly a factor
   of three

 - feature: acl dataset - ip6 addresses are now supported in ACLs

 - feature: added --enable-asserts configure option to enable
   compilation of debugging assertions; assertion checking is
   disabled by default

 - featurette: zero-length "wildcard" IP4 CIDR prefixes are now
   allowed in ip4trie and acl datasets.
Updated net/rbldnsd to 0.997a
Improve binary package:

* Reduce potential patch conflicts by switching more DESTDIR support to sed
* Enable `qmail-netqmail` by default
* Install `qmail-viruscan` signatures via CONF_FILES
* With `tls` option, don't generate cert, instruct the user at INSTALL time

That last change also fixes the source build with `tls` enabled on
systems that don't already have a /var/qmail/control, as reported
by Thomas Lazar on pkgsrc-users@.

While here, add a comment with the new location of the qregex patch.
Since it's named strangely, I've also placed a traditionally-named
copy on ftp.n.o.

Bump PKGREVISION.
Updated mail/qmail to 1.03nb19
Remove curl from Makefile, it's an option.
Add proper curl option handling to buildlink3.mk.

From Leonardo Taccari.
Add "# used by" lines.