testclient.exe installed under MSVC

My annual audit for executables missing Windows icons turned up these:

        pginstall/bin/testclient.exe
        pginstall/bin/uri-regress.exe

I was going to add the icons, but I felt the testclient.exe name is too
generic-sounding to be installed.  testclient originated in commit ebc8b7d.  I
recommend ceasing to install both programs under MSVC.  (The GNU make build
system does not install them.)  If that's unwanted for some reason, could you
rename testclient to something like libpq_test?

Thanks,
nm