Added InMemoryCatalogue and OracleCatalogue.

PLEASE NOTE:

    The tapeserverd daemon (ProcessForker::runDataTransferSession)
    now reads the connection details of the catalogue database from
    the following configuration file at the beginning on each tape
    mount:

        /etc/cta/cta_catalogue_db.conf

    Installing the CTA rpms will install the following example file:

        /etc/cta/cta_catalogue_db.conf.example

    This example file document the syntax of the database connect
    details.

    For the time being the contents of cta_catalogue_db.conf should
    simple be:

        in_memory

    This means the tapeserverd daemon will use an in-memory
    catalogue database.