Better psql tab-completion support for schemas and tables

(oops, this time with -c, thanks Alvaro)

Full support for all schema and table name combinations when
getting a list of attributes. All of the following will now work:

select * from information_schema.columns where <tab>
select * from foo where <tab>
select * from "user" where <tab>
select * from "foo" where <tab>
select * from "Uppercase".lower where <tab>
select * from "gtsm.com"."foo.Bar" where <tab>
select * from "GTSM.com".foo where <tab>

Also applies to other places that get lists of columns: insert into,
alter table, create index, etc.

--
Greg Sabino Mullane greg@turnstep.com
PGP Key: 0x14964AC8 200710211532
http://biglumber.com/x/web?pk=2529DF6AB8F79407E94445B4BC9B906714964AC8