reorg - pg_reorg: Use one of not-null unique keys to identify rows when

Log Message:
-----------
Use one of not-null unique keys to identify rows when the target table doesn't
have a primary key. Some of users want to use not-null unique keys rather than
primary keys because postgres doesn't support REINDEX PRIMARY KEY CONCURRENTLY.

- Support 9.1dev.
- Improve Makefile to use PGXS automatically.

Modified Files:
--------------
pg_reorg:
Makefile (r1.5 -> r1.6)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/reorg/pg_reorg/Makefile?r1=1.5&r2=1.6)
pg_reorg/bin:
Makefile (r1.7 -> r1.8)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/reorg/pg_reorg/bin/Makefile?r1=1.7&r2=1.8)
pg_reorg.c (r1.16 -> r1.17)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/reorg/pg_reorg/bin/pg_reorg.c?r1=1.16&r2=1.17)
pg_reorg/bin/expected:
reorg.out (r1.8 -> r1.9)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/reorg/pg_reorg/bin/expected/reorg.out?r1=1.8&r2=1.9)
pg_reorg/bin/sql:
reorg.sql (r1.8 -> r1.9)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/reorg/pg_reorg/bin/sql/reorg.sql?r1=1.8&r2=1.9)
pg_reorg/lib:
Makefile (r1.6 -> r1.7)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/reorg/pg_reorg/lib/Makefile?r1=1.6&r2=1.7)
pg_reorg.sql.in (r1.8 -> r1.9)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/reorg/pg_reorg/lib/pg_reorg.sql.in?r1=1.8&r2=1.9)
reorg.c (r1.19 -> r1.20)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/reorg/pg_reorg/lib/reorg.c?r1=1.19&r2=1.20)
pg_reorg/lib/pgut:
pgut-be.h (r1.6 -> r1.7)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/reorg/pg_reorg/lib/pgut/pgut-be.h?r1=1.6&r2=1.7)