Thanks to Pau Garcia i Quiles for the inspiration for the patch.
I've tweaked it a bit compared to what's in the bug tracker: this
commit does not allow empty global variable names.

I also added usage of the new feature to an existing test. Although
it has no effect on the resulting Visual Studio projects, you can
verify that the VSResource test produces a non-empty globals section
in the generated .vcproj(x) files.