Add a check for existing addons.
Rename the plugin class.
Rename stuff to "addon catalog".
Include the correct header reference.
Create README.md

Since it just holds a link to the working group page, this closes #6.
Create posts from info passed. Update functionality needs to be added ASAP.
Update posts with an existing guid. Needs rigorous testing, as it seems to allow new posts to be created. Closes #24.
Store the GUID in uppercase if you check for it in uppercase.
Actually store the repo_url like it should, per mikelietz/post_receive#12
Clean up some stuff, add the start of downloads
Change vocab name to const, account for PHP 5.3 closure and  weirdness.
Update ping entrypoint for plugins.
Use correct constant.  Fixes #25.
Add hash field.