Merge pull request #751 from pulp/mhrivnak-231-release-notes

adding 2.3.1 release notes
1048297 - pulp-dev.py sets the CA cert and key world readable.

It also makes /etc/pki/pulp/content owned by Apache.
Fixing a typo in glossary
Merge branch 'pulp-2.3'
Merge branch 'master' into distributed-tasks