Import Studio Registries using REST

From now, we have a dedicated endpoint to let us push some operations from Nuxeo IDE.

We'd like to be able to push to any registry, like "facets", "permissions", "doctypes", ... Also, to be able to push things to the registry from several sources, it could be interesting to have two differents mode:

• "replace" mode: that overrides the existing registry
• "merge" mode: that replace the existing ones, add the new ones

From the endpoint point of view:

• we need one endpoint that can read a JSON with several kind of registries in
• endpoint must be accessible using Token Auth (api v2 is right, not v1)
• we deprecated the old Nuxeo IDE endpoint

From Studio point of view:

• We kept the IDE registry - for now -
• We create a new folder "Automatic Registries" containing all registry (using the same kind of UI / features than Nuxeo IDE ones)