pgsql: Remove maintainer-check target, fold into normal build

Remove maintainer-check target, fold into normal build

make maintainer-check was obscure and rarely called in practice, and
many breakages were missed. Fold everything that make maintainer-check
used to do into the normal build. Specifically:

- Call duplicate_oids when genbki.pl is called.

- Check for tabs in SGML files when the documentation is built.

- Run msgfmt with the -c option during the regular build. Add an
additional configure check to see whether we are using the GNU
version. (make maintainer-check probably used to fail with non-GNU
msgfmt.)

Keep maintainer-check as around as phony target for the time being in
case anyone is calling it. But it won't do anything anymore.

Branch
------
master

Details
-------
http://git.postgresql.org/pg/commitdiff/5dd41f3574871757e6b8e2a16b3e736fee36c20d

Modified Files
--------------
GNUmakefile.in | 2 --
config/programs.m4 | 5 +++++
configure | 14 ++++++++++++++
doc/Makefile | 2 +-
doc/src/Makefile | 2 +-
doc/src/sgml/Makefile | 6 +++---
src/Makefile.global.in | 5 +++--
src/backend/catalog/Makefile | 3 ++-
src/backend/common.mk | 2 +-
src/include/Makefile | 3 ---
src/nls-global.mk | 11 ++---------
11 files changed, 32 insertions(+), 23 deletions(-)