pgsql: Display incoming as well as outgoing foreign-key constraints in

Log Message:
-----------
Display incoming as well as outgoing foreign-key constraints in psql's
\d output for a table.

Kenneth D'Souza, some changes by myself.

Modified Files:
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pgsql/src/bin/psql:
describe.c (r1.164 -> r1.165)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/bin/psql/describe.c?r1=1.164&r2=1.165)