This one is just a bugfix in extconf.rb when appending to $CFLAGS

Also note, as of this release, I have started pushing to gemcutter
instead of rubyforge, so to install, you'll need to install gemcutter,
tumble and install ffi.

btw, can windows users please test the binary mswin32 and mingw32 gems
to make sure they install correctly from gemcutter?