Add vendor import for pjdfstest

This vendor import code was obtained from
https://github.com/pjd/pjdfstest/commit/abf03c3a47745d4521b0e4aa141317553ca48f91

Approved by: rpaulo (mentor)
Phabric: D743
Sponsored by: EMC / Isilon Storage Division
Fix a typo in the upgrade directions

MFC after: 2 weeks
Sponsored by: EMC / Isilon Storage Division
Import pjdfstest from ^/vendor/pjdfstest/abf03c3a47745d4521b0e4aa141317553ca48f91

- Remove tools/regression/pjdfstest
- Add upgrade directions for contrib/pjdfstest
- Add a note to UPDATING for the move (the reachover Makefiles are coming
  soon)

Functional differences:
- ftruncate testcases are added from upstream (github)

Non-functional differences:
- The copyright for the project has been updated to 2012
- pjd's contact information has been updated

Discussed with: -testing, jmmv, pjd
MFC after: 2 weeks
Sponsored by: EMC / Isilon Storage Division