Supporting src/test/modules in MSVC builds

Hi all,

As mentioned previously
(CAB7nPqSCphafxS2RzeB-FBccjqiKnQXJhLoZtkggiM1MF5Xv4A(at)mail(dot)gmail(dot)com),
attached are patches to add support for src/test/modules in MSVC
builds, modules whose tests are not supported since they have been
moved from contrib/:
- 0001 adds support for the build portion.
- 0002 adds support for the installation. I arrived at the conclusion
that those modules should be installed by default, because
contribcheck relies on the fact that tests should be run on a server
already running, and modulescheck should do the same IMO.
- 0003 adds a new target modulescheck in vcregress.

Patches 0001 and 0003 are based on some previous work from Alvaro,
that I modified slightly after testing them. Note that this split is
done to test each step on the build farm for safety.
Regards,
--
Michael