Releasing 3.5.7

git-svn-id: https://plugins.svn.wordpress.org/addthis/trunk@856404 b8457f37-d9ea-0310-8a92-e5e31aec5664
* Releasing updated version
* Resolved conflict with another plugin

git-svn-id: https://plugins.svn.wordpress.org/addthis/trunk@857043 b8457f37-d9ea-0310-8a92-e5e31aec5664