Fixing bug in session when using machine credentials

get_unique_record was being called on site table without adding the
service_id as part of the unique key
Adding user/pass/site/role management to cenozo_manager

The cenozo_manager now has methods to override the default user, password,
site and role to use when communicating with other cenozo applications.

Also removing old code from before there was a central "cenozo" database
which is no longer necessary.
Merge remote branch 'origin/release' into develop