Porting change.
Now builds under Cygwin with only a few filthy
hacks. New undoc'd --gccver=2 flag allows Cygwin users to build
P4Ruby using the gcc-2 package rather than the default compiler
which is currently gcc 3.2.3. They have to do this because the
Perforce API is not yet available in a gcc-3 version for Cygwin.