udpate Latvian and add recommended plugins

git-svn-id: https://plugins.svn.wordpress.org/polylang/trunk@1014858 b8457f37-d9ea-0310-8a92-e5e31aec5664
recommended plugins again

git-svn-id: https://plugins.svn.wordpress.org/polylang/trunk@1014860 b8457f37-d9ea-0310-8a92-e5e31aec5664