Added uninstall hook to remove options when uninstalled.

git-svn-id: https://plugins.svn.wordpress.org/rackspace-cloud-files-cdn/trunk@933670 b8457f37-d9ea-0310-8a92-e5e31aec5664
Fixed uninstall hook.

git-svn-id: https://plugins.svn.wordpress.org/rackspace-cloud-files-cdn/trunk@933671 b8457f37-d9ea-0310-8a92-e5e31aec5664