access: customized access configuration

* Adds new inspire module overlay for Invenio access module.

* Sets up some default DEMO cataloger roles.

Signed-off-by: Jan Aage Lavik <jan.age.lavik@cern.ch>
Actually, this will be merged (or added) with what is inside the `DEF_ROLES` etc. variables in `access/local_config.py`. Our rules would only override any duplicate rules though when running `webaccessadmin -aD ` (which happens upon `database create`).