Stable is 0.5.8

git-svn-id: https://plugins.svn.wordpress.org/papercite/trunk@855596 b8457f37-d9ea-0310-8a92-e5e31aec5664
Cache was not cleared properly in 0.5.8: fixed

git-svn-id: https://plugins.svn.wordpress.org/papercite/trunk@856335 b8457f37-d9ea-0310-8a92-e5e31aec5664