Uploading v2.3.8.

git-svn-id: https://plugins.svn.wordpress.org/fetch-tweets/trunk@1035192 b8457f37-d9ea-0310-8a92-e5e31aec5664
Marked v2.3.9 as stable.

git-svn-id: https://plugins.svn.wordpress.org/fetch-tweets/trunk@1035193 b8457f37-d9ea-0310-8a92-e5e31aec5664