(Issue 970) Do not update discussion library if discussion timestamp was not updated
(Issue 970) Don't allow library index updates that result in accidental deletions
(Issue 970) Add comment to new test
(Issue 970) Only touch discussion on share if it is within the update threshold
Support short Flickr URLs in the PP

Brought in support for flic.kr/p/id type URLs
Mocking the flickr API when integration tests are
not being run
Merge pull request #971 from simong/flickr-short-urls

Flickr shortened links not processed
Merge pull request #970 from mrvisser/issue-970

Adding a user as a member to a discussion item doesn't make the discussion show up in that user's discussion library
Merge branch 'master' of https://github.com/oaeproject/Hilary