Xconq for Windows

[Jim Kingdon]

> Perhaps the best solution would be what the tcltk people did
> themselves, i.e. to put the platform-specific code in separate mac,
> win and unix directories within the tcltk folder?

Seems like overkill at least for now.  The platform-specific code is
well separated out into tkwin.c, tkmac.c, and tkunix.c (well, tkunix.c
doesn't have that name yet, but it presumably will soon).