Merge branch 'release/2.1.13'

* release/2.1.13:
  version bump
Instapaper fixed the timestamps in their RSS feed

So the hack for dealing with that can be removed
Merge pull request #311 from ArjenSchwarz/master

Instapaper fixed the timestamps in their RSS feed
Fixing levenshtein requires
Merge branch 'master' into develop

* master:
  Instapaper fixed the timestamps in their RSS feed