pgsql: Clarify code to double \\ and '.

Log Message:
-----------
Clarify code to double \\ and '.

Modified Files:
--------------
    pgsql/src/bin/initdb:
        initdb.c (r1.88 -> r1.89)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/bin/initdb/initdb.c.diff?r1=1.88&r2=1.89)
    pgsql/src/bin/psql:
        describe.c (r1.118 -> r1.119)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/bin/psql/describe.c.diff?r1=1.118&r2=1.119)
        large_obj.c (r1.37 -> r1.38)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/bin/psql/large_obj.c.diff?r1=1.37&r2=1.38)
    pgsql/src/pl/plpgsql/src:
        gram.y (r1.77 -> r1.78)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/pl/plpgsql/src/gram.y.diff?r1=1.77&r2=1.78)