Git/Conversion/Extensions queue

Now that the initial dust has settled on migration of Wikimedia-deployed extensions and MediaWiki core, we're ready to start migrating other existing extensions into git. I plan to do these on a rolling basis as they're added to the list.

What I need from you

 * The name of the extension
 * Who is going to maintain it--gerrit username(s) please
 * Any other specific information you think would be useful
 * This includes specific branches you want migrated (please do not include release branches from 1.19 and below unless you're actively backporting to them)