fixed customcss and customjs attributes

Added fix for inline callouts when using prettify (both the bullet and the number between brackets are shown). I could solve this by adding the _conum_ class to the _b_ element so that the _b_ element can be hidden with css: `.conum + b, b.conum { display: none; }`
I'd like to leave this one off and only add the conum class to b when not using icons.