duplicative -DFRONTEND flags from many Makefiles.  We still need Makefile
control of the symbol in a few places that compile frontend-or-backend
src/port/ files, but it's a lot cleaner than before.

Hiroshi Saito

back-stamped for this.

Tag appropriate files for rc3

Also performed an initial run through of upgrading our Copyright date to
extend to 2005 ... first run here was very simple ... change everything
where: grep 1996-2004 && the word 'Copyright' ... scanned through the
generated list with 'less' first, and after, to make sure that I only
picked up the right entries ...

make sure the $Id tags are converted to $PostgreSQL as well ...

initdb/regression tests pass.

spacing.  Also adds space for one-line comments.

tests pass.

are now separate files "postgres.h" and "postgres_fe.h", which are meant
to be the primary include files for backend .c files and frontend .c files
respectively.  By default, only include files meant for frontend use are
installed into the installation include directory.  There is a new make
target 'make install-all-headers' that adds the whole content of the
src/include tree to the installed fileset, for use by people who want to
develop server-side code without keeping the complete source tree on hand.
Cleaned up a whole lot of crufty and inconsistent header inclusions.