mb and ecpg regression tests

We've had ecpg regression tests being doing by the buildfarm for a
while, but they are not enabled for MSVC. Also, buildfarm has never
supported doing MBCS regression tests. In both cases the regression
tests are driven by Unix shell scripts, and in the MBCS case at least,
the script would need plenty of love before it would be suitable for the
buildfarm even on Unix.

Back when we were thinking of supporting MSVC builds, we thought that
everything would need to be a C program, and so we rewrote the main
regression script in C, for example. However, now we have a build system
for MSVC we can see that its main infrastructure is in fact perl, so I
think what we need to do is to convert the MBCS and ECPG regression
drivers to perl rather than C - which should be far, far simpler task.

I'm going to try to get these done and supported by the buildfarm by the
time we get to Beta.

cheers

andrew