Minor bug fix upgrades for third party dependencies

Addresses the issue that several third party libraries used by dCache
have bug fix releases newer than the version we use.

I would have liked to get these committed before 2.6.0 got released,
but didn't have the time to do it.

Target: master
Request: 2.6
Require-book: no
Require-notes: yes
Acked-by: Tigran Mkrtchyan <tigran.mkrtchyan@desy.de>
Patch: http://rb.dcache.org/r/5549/
(cherry picked from commit e9e94ce5da598f9d5d6a57ee551504fcfcce44e7)
Merge pull request #35 from gbehrmann/fix/2.6/rb5549

Minor bug fix upgrades for third party dependencies