Pretty printing code on mobile

Before anyone files a bug report, we are no longer pretty printing (using javascript to add line numbers & color coding) code snippets when on mobile browsers for performance reasons. It's not that it was particularly non-performant on mobile. It's rather just that I'm working hard to improve performance across a variety of devices, and I felt like it wasn't worth the trade-off, given it's an extra second or so of javascript parsing in exchange for making code not all that much more readable when on a mobile device.