Update README to match new features etc.

[tamw-wnet]

@jwcounts @davidmpurdy we're right on the verge here of being ready to release v1.9 I think. I'll update the README with new screenshots, check what versions of WP its tested against, etc.

Once we actually release 1.9 tag, I'll submit it to the Wordpress Plugin Repo as an update. I'm assuming that's going to be a pain in the behind because the 'ownership' has changed.