fix handling of DN with comma as per rfc1779

Ticket: http://rt.dcache.org/Ticket/Display.html?id=8285
Ticket: http://rt.dcache.org/Ticket/Display.html?id=8312
Merge pull request #130 from kofemann/fix-comma

fix handling of DN with comma as per rfc1779
ssl-proxies: fix test user certificate
tests: disable certificates caching to keep test happy
Merge remote-tracking branch 'upstream/master'