porting to windows

[Ulf Hermann]

Hi,

I just tried to post the patch that adds all the gnulib modules. I suspect the mailing list doesn't like it because it's 4.8MB of diff. I've merged all the single "add xyz gnulib module" patches into one because you cannot sensibly reorder or skip any of them anyway. gnulib likes to keep several configuration files that change with every added module and trying to handle this using git results in lots of conflicts. I can, of course, change the selection of gnulib modules if necessary.

This is the change I tried to post: https://codereview.qt-project.org/#/c/186564/

br,
Ulf