Windows install to custom location after building from source

["Martin v. Löwis"]

> BTW what are your feelings on a patch to msi.py to change the
> names of the directories it's looking for to pick up the Tk
> licenses? It's a bit of a grey area since the only "canonical"
> reference I can find is the externals checkout from within
> tools\buildbot: you might as well argue that it's *that*
> which should be changed.

Never touch a running system :-) If I can leave the tcl directories
where I have them, and just check them out a second time (or
perhaps just the license), that would be fine with me.

Regards,
Martin