reorganizing, moved .mat files and changed "load $foo" to "load ../matfiles/$foo"

[chrishwiggins]

Dear Dr. Pei

Thanks for this great work and for sharing via GitHub.

An idea: to make the code+data easier to navigate please consider adding as files rather than as zipfiles. here's a pull request that so organizes. I had to change all the "load" commands in .m files to "load ../matfiles/$foo" to respect this re-factor

thanks again, let me know if i can provide any additional info