fix retrieving of file handles, so that FXApp#addInput works with ruby 1.8.7, 1.9.2 and rubinius under Linux (win32 not tested yet)

support rubinius

add tasks for downloading and cross compilation of libfox, fxscintilla and depending libraries for win32

C++ source and header files.

I added -I/usr/local/include to $CFLAGS and -L/usr/local/lib to
$LDFLAGS for the Darwin build, so that it would find the jpeg and
tiff libs on my system.

and -L/usr/X11/lib to $LDFLAGS when building on OS X. This will ensure that
it picks up the built-in PNG library.

This reverts commit 13dbbd0f.

to an absolute path, so that the rake-compiler task can see those
files.