Upgrade to version 3.13

Major updates/fixes to the distfile handling code
=================================================
* Make all parts of the code SUBDIR-safe (most were already)
  - Fix a few places where the relativity of the cwd was not respected,
    most often resulting in files not being deleted that should be
* Move the storage of the distfile info back to /var/db/pkg where it
  should have been all along. Mostly for correctness, but also to deal
  with the problem of non-UNIQUENAMEs causing the wrong files to be
  deleted with -d.
* Clean up the old /var/db/ports/*/distfiles files after reading them,
  and delete the directory if it's empty. Since we are doing this
  unconditionally now, there is no longer a need for delete_dist_list().
  The new ones will live and die with the rest of the package directory.
* Update some of the messages printed out for distfile-related things
  to make it more clear what's going on.
* Check DI_FILES to see if the distfile could be valid for another port
  in more places, so add a function to deal with the common ones.
* When checking DI_FILES, anchor the grep pattern with a ^ to
  avoid false positives

Other code changes
==================
* Make the whitespace more consistent
* Various minor improvements, mostly to avoid unnecessary forking

UI Change
=========
* When using -i and there is an +IGNOREME file, the default should be no

0 files changed, 0 insertions, 0 deletions