gEDA-dev: Building pcb on cygwin from fresh CVS CO

[DJ Delorie]

> IMHO it is missing "puller.txt", "thermal.txt", "puller.png"and
> "thermal.png", complains about it and then bails out.

The png's at least are built with pcb itself, and won't happen unless
you enable maintainer mode, which adds some uncommon programs to the
prerequisites.  Just skip the docs for now, or re-configure with
--enable-maintainer-mode.