Add "Tumblrize Everything" feature to batch-crosspost site archives.

git-svn-id: https://plugins.svn.wordpress.org/tumblr-crosspostr/trunk@855117 b8457f37-d9ea-0310-8a92-e5e31aec5664
Update readme, add "Tumblrize Archives" screenshot, version bump to 0.6.

git-svn-id: https://plugins.svn.wordpress.org/tumblr-crosspostr/trunk@855118 b8457f37-d9ea-0310-8a92-e5e31aec5664