Release 2.3, complete fork by netj

- Rewrote README (in Markdown).
- New place to distributed built versions. (file downloads are no longer
  supported at Github)
- Forked Sparkle appcast: new key, and URL pointing to my Dropbox.
- Wrote a small shell script for simplifying the process of creating zip
  archives, signing and deploying updates.
- Merged alanshutko's Google Reader URL fix.
- Growl framework 2.0.1.
  Notification Center support comes for free on OS X 10.8!
- Sparkle Korean language support.