Follow up from #678. cx_freeze doesn't allow us to set the file description, version, etc. So we have to patch it up after it runs, before we package things.
Done in r15919. Bonus: the description is now more correct in the task manager.
FWIW, there are many other tools we could have used instead of How do I set the version information for an existing .exe, .dll? but most of them are awful, without source or just buggy. It does require visual studio to build from source... PITA - I don't have time to port it to mingw.
this ticket has been moved to: https://github.com/Xpra-org/xpra/issues/1523