Complete changes began by previous patch(es) (things that were missed):

The internal header should not precede polymorphic definition in:
user_record.c
seuser_record.c
iface_record.c
boolean_record.c

Include guards added for:
context_internal.h

typedef define guard added for:
port_record.h
(and include port_internal.h in port_record.c)
=========
Then... move all extern declarations of the record method table
into the internal header where they belong - that requires including
database.h, but that's okay, because the previous patches fixed
issues relating to that.