Button Image Alignment Fix (#272, #30)

Changed button element from button to div for consistent rendering
across browsers.
Button Tab Index Fix
Better Button Fix

Wrapped the images in a single div and used that as the content of a
button element.
Code cleanup

Removed commented and leftover code
Merge pull request #303 from msalsbery/Button-Images

Button Image Alignment Fix (#30)
Changelog for #303