pgsql: Improve reporting of dependencies in DROP to work like the scheme

Log Message:
-----------
Improve reporting of dependencies in DROP to work like the scheme that we
devised for pg_shdepend, namely the individual dependencies are reported as
DETAIL lines rather than coming out as separate NOTICEs.  The client-side
report is capped at 100 lines, but the server log always gets a full report.

Modified Files:
--------------
    pgsql/src/backend/catalog:
        dependency.c (r1.74 -> r1.75)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/catalog/dependency.c?r1=1.74&r2=1.75)
    pgsql/src/test/regress/expected:
        alter_table.out (r1.108 -> r1.109)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/expected/alter_table.out?r1=1.108&r2=1.109)
        create_view.out (r1.12 -> r1.13)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/expected/create_view.out?r1=1.12&r2=1.13)
        domain.out (r1.44 -> r1.45)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/expected/domain.out?r1=1.44&r2=1.45)
        foreign_key.out (r1.46 -> r1.47)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/expected/foreign_key.out?r1=1.46&r2=1.47)
        inherit.out (r1.25 -> r1.26)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/expected/inherit.out?r1=1.25&r2=1.26)
        namespace.out (r1.4 -> r1.5)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/expected/namespace.out?r1=1.4&r2=1.5)
        sequence.out (r1.10 -> r1.11)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/expected/sequence.out?r1=1.10&r2=1.11)
        truncate.out (r1.15 -> r1.16)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/expected/truncate.out?r1=1.15&r2=1.16)
    pgsql/src/test/regress/output:
        tablespace.source (r1.6 -> r1.7)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/output/tablespace.source?r1=1.6&r2=1.7)