escape value in css inspector

as mentioned here, having a double quote in the css field causes an issue:
http://www.concrete5.org/developers/bugs/5-6-0-2/adding-double-quote-in-add-your-css-truncates-css-after/

I thought about adding htmlentities to the form helper method hidden and inputType. I think
it would be correct but I'm not sure if it would cause other problems.