gerrit/plugins

If you are adding a directory here:

- Search all pom.xml files for "CORE PLUGIN LIST".
- Add the new plugin to that location.
- (optional) Thank the Maven developers for making this easy.

- Ensure the plugin's pom.xml <version> is the same as Gerrit's
  own pom.xml(s). Gerrit will only embed a plugin that has the
  same version as itself.

- Register the plugin as a submodule with git submodule.