pgsql: Try connecting to both postgres and template1 databases to do the

Log Message:
-----------
Try connecting to both postgres and template1 databases to do the initial
inspection of shared catalogs. This allows pg_dumpall to continue to
work with pre-8.1 servers that likely won't have a database named postgres.
Also, suppress output of SYSID options for users and groups, since server
no longer does anything with these except emit a rude message.
There is much more to be done to update pg_dumpall for the roles feature,
but this at least makes it usable again. Per gripe from Chris K-L.

Modified Files:
--------------
pgsql/src/bin/pg_dump:
pg_dumpall.c (r1.62 -> r1.63)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/bin/pg_dump/pg_dumpall.c.diff?r1=1.62&r2=1.63)