update readme and screenshots

git-svn-id: https://plugins.svn.wordpress.org/qqworld-speed-4-china/trunk@1034888 b8457f37-d9ea-0310-8a92-e5e31aec5664
update language

git-svn-id: https://plugins.svn.wordpress.org/qqworld-speed-4-china/trunk@1034889 b8457f37-d9ea-0310-8a92-e5e31aec5664