Missing file versions for a bunch of dll/exe files in Windows builds

Hi all,

A colleague of mine pointed out that the file version is missing in a
couple of dll and exe files when building on windows using the
community scripts in src/tools/msvc. After having a closer look, I
noticed that a *lot* of files are missing the shot:
- all the exe/dll in contrib/
- dll of PL languages (perl, python, tcl, pgsql)
- libpqwalreceiver, snowball
- ecpg stuff
- regression and isolation test stuff
- conversion_procs thingies
Having a version number associated to a build is important for all
companies creating builds of Postgres on Windows, so it would be good
to have the patch attached applied and back-patched.

Regards,
--
Michael