#362 Remove Old Datastore

Remove controller, routing and tests related to old datastore.

Note one collateral piece of removal: the api_data method in package, and hence the removal of support for Data API Info to work in absence of AJAX. See this commit for details: https://github.com/okfn/ckan/commit/27361b88e1b8fe2167f83bd9cb5cf70e953ce052