Upload and Maintain GeoServer schema files

[ScottEvil]

As a user I need to be able to upload schema files to GeoServer and maintain the domains on them (add, modify, remove) so that clients like MapLoom and Arbiter can be populated with drop downs during edit process.

• [ ] Upload an xsd to become a schema file for a specific layer
• [ ] Add, modify, remove the domain values in the schema file

[garnertb]

This may be a good approach for uploading and modifying schemas.

http://docs.geoserver.org/stable/en/user/rest/api/datastores.html#workspaces-ws-datastores-ds-file-url-external-extension