Open help sidebar links in new tab or window.

git-svn-id: https://plugins.svn.wordpress.org/tumblr-crosspostr/trunk@857365 b8457f37-d9ea-0310-8a92-e5e31aec5664
Add French translations, update readme, version bump to 0.6.2.

git-svn-id: https://plugins.svn.wordpress.org/tumblr-crosspostr/trunk@857367 b8457f37-d9ea-0310-8a92-e5e31aec5664