improve cross-linking between Core /ORM for schema arg

improve cross-linking between Core /ORM for schema arg

this should be backported to 1.3 as well to as much a degree
as possible.

Includes a new recipe to set the default schema name
on connect.   this will only work on 1.4, but also requires
that we fix #5708 for it to work fully.

Change-Id: I882edd5bbe06ee5b4d0a9c148854a57b2bcd4741