Documentation file compilation procedures

I just found the index not matching the files; the reason is that the
HTML generated files where used instead of HTMLHELP generated. The patch
needed to generate htmlhelp compatible html files is freshly posted to
pgsql-patches.

Doc HOWTO:
- cd pgsql/doc/src/sgml
- make htmlhelp
- Change the links to pg/* in index.hhk and toc.hhc
- copy html files to en_US/pg
- if necessary, join src/sgml/index.hhk into en_US/pgadmin3.hhk and
src/sgml/toc.hhc into en_US/pgadmin3.hhc. The pg/* versions should be
removed.
- execute pgadmin's help function, in order to have pgadmin2.hhp.cached
recreated
- touch pgadmin3.hhc and pgadmin3.hhk with Html Workshop, to make sure
the format is ok (if not, it will crash when generating pgadmin3.chm)
- create en_US/pgadmin3.zip.
- create en_US/pgadmin3.chm.
- clean up: in en_US, only pgadmin3.zip and tips.txt are needed.

Regards,
Andreas