Adds a button to allow you to widen the container when viewing unified diffs
Allows you to widen the container that holds code (individual files and diffs) up to 95% of the width of your window. It also reverts it back to normal when you click it again. The other button reloads the page without whitespace in diffs by adding 'w=1' to the URL query string; clicking it again will reload the page with whitespace.
