BatchUploader: more RESTful interface
- Introduce a more RESTful interface to batchuploader/robotupload allowing to PUT/POST MARCXML as the body of the HTTP request. (closes #976)
- Introduce a new nonce argument to the bibupload/robotupload stack, in order to allow clients to uniquely identify multiple feedbacks POSTed to the callback_url. (closes #977)
- Introduce new make_user_agent_string function to urlutils to use a uniform User-Agent string accross Invenio HTTP requests. (addresses #997)
- Drop the comma-separated list based CFG_BATCHUPLOADER_WEB_ROBOT_AGENT invenio.conf variable in favour of regexp-based CFG_BATCHUPLOADER_WEB_ROBOT_AGENTS variable.