ports-mgmt/pkg-devel: update to 2.3.1

Changes:
- New OSVF Parser
- New CPE Parser/Emitter
- Lots of code cleanup and simplification
- Add support for system triggers (triggers in /usr/share/pkg/triggers)
- pkg check now respects -r (rootdir)
- relax ABI checking
- Lots of improvements and bugs fixes regaring BACKUP_LIBRARIES features
- Integrate BACKUP_LIBRARIES in the solver
- Add vital flag to the list of flag which we need to consider for package reinstallation
- tack uname, gname, mtime, permissions and fflags in the db and in the manifest
  instead of relying on the tar informations. which gives us pkg check -m to check for
  for metadata changes.
- METALOG: add entries for intermediate directories
- better 404 reporting
- fix return code for pkg upgrade -n
- new pkg sets alias example in default pkg.conf
- new DEBUG_SCHEDULER_DOT_FILE option to generate a graphviz DOT format for the job graph
- loosen ordering for upgrade jobs (reduces a lot the number of split upgrades and speed up
  the scheduler on setup with large number of packages.)