Dariusz Olszewski's changes to support compiling for PocketPC. This

Dariusz Olszewski's changes to support compiling for PocketPC. This
is mostly done with ifdefs in windows.c; so mkfiles.pl generates a
new makefile (Makefile.wce) and Recipe enables it, but it's hardly
any different from Makefile.vc apart from a few definitions at the
top of the files.

Currently the PocketPC build is not enabled in the build script, but
with any luck I'll be able to do so reasonably soon.

[originally from svn r7337]