Update trunk for 2.9.7

git-svn-id: https://plugins.svn.wordpress.org/wp-to-twitter/trunk@1021167 b8457f37-d9ea-0310-8a92-e5e31aec5664
Readme; update notice.

git-svn-id: https://plugins.svn.wordpress.org/wp-to-twitter/trunk@1021168 b8457f37-d9ea-0310-8a92-e5e31aec5664
Update to 2.9.7.

git-svn-id: https://plugins.svn.wordpress.org/wp-to-twitter/trunk@1021173 b8457f37-d9ea-0310-8a92-e5e31aec5664