Smarter Quote post type, use content after `</blockquote>` as "Source."

git-svn-id: https://plugins.svn.wordpress.org/tumblr-crosspostr/trunk@850759 b8457f37-d9ea-0310-8a92-e5e31aec5664
Update readme, version bump to 0.4.

git-svn-id: https://plugins.svn.wordpress.org/tumblr-crosspostr/trunk@850760 b8457f37-d9ea-0310-8a92-e5e31aec5664