Image Slider (Alpha); Other minor changes

Super-basic version of the image slider. It works fine, but still has a lot of work to be done on it.
Added images for testing image resizing, etc.
Modified head.php for compatibility.
Merged all javascript into jsFunctions.js.
Gave header z-index of 5 to keep it above image slider.
Fixed typo in about.php.

TODO: 
Better commenting in js file.
Prefix class/id on image slider css.
Different transitions in image slider.
Autoplay.
Small bug fixes.