setup versioning

[DJ Delorie]

I was just thinking that the CVS revision of "ChangeLog" might be a
good automatic version number for setup (aside from the fact that it's
1.x instead of 2.x, but I can fix that).

Another thought is to auto-tag all the source files, and provide a
dialog that shows them all, for troubleshooting purposes.  A grep or
sed could be used to build a .h from all the *.c keywords in their
comments.

Comments?