Update files for 2.1.0

git-svn-id: https://plugins.svn.wordpress.org/multilingual-press/trunk@996645 b8457f37-d9ea-0310-8a92-e5e31aec5664
Update files for 2.1.0

git-svn-id: https://plugins.svn.wordpress.org/multilingual-press/trunk@996646 b8457f37-d9ea-0310-8a92-e5e31aec5664
Update stable tag to 2.1.0

git-svn-id: https://plugins.svn.wordpress.org/multilingual-press/trunk@996649 b8457f37-d9ea-0310-8a92-e5e31aec5664