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

the previous warning level the user had set instead of just assuming
that warnings were turned on. [#8 state:resolved]

C++ source and header files.

"lyle@lylejohnson.name" in all SWIG interface files.

By default it looks like rake-compiler doesn't modify the gem spec
appropriately when we're cross-compiling for multiple Ruby versions.
Added some lines to remove "lib/fox16.so" from the gem spec's list
of files to include, and then added "lib/1.8/fox16.so" and "lib/1.9/fox16.so"
back to the list, so that we get the correct result.

determine which shared library to load.

If RUBY_PLATFORM says we're on Windows, this loader will look under
a version-specific directory to try to load the extension. For other
platforms, it will just load the appropriate shared library from
the current directory.

Followed the instructions at http://github.com/luislavena/rake-compiler
to modify the ExtensionTask so that it supports cross-compilation. This
included moving the 'config_options' that were being used for a
RUBY_PLATFORM of "mingw" into the new 'cross_config_options' parameter.

In the interest of keeping this as simple as possible, I've extracted
the source files for the FXRuby User's Guide into a separate project
(fxruby-guide).

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.