modify sample template and add new css/script for new numbered code.

The line numbers are included inside the <pre> block initially, but
hidden, so this script moves the numbers to a separate block on
the left and makes them non-selectable. Also includes script for
features like single-click to highlight a line of code and double-click
to invoke the link for that line.

Change-Id: I17ebb1255ff036948028b4722cc8e9758fb96553