I've got the repository back online again after a long absence. However, because of a bug with some of the dependency code on Stencyl's side, it will try to update you to versions you can't use if you're not on 3.5.0 yet.
For 3.4.0, the latest extensions can be found here.
http://www.polydes.com/3.4.0-extensions/If you're on 3.5.0, go ahead and use the repository to manage extension updates.
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I've also split up the git repository into a git repository for each project, and moved them all off of my personal github account to a new group account.
https://github.com/polydes