enable IE8 to set html into style element

- Inspired of code suggested by @swhiteman, and spec based on
jsFiddle
http://jsfiddle.broadleafsystems.com/sLtph/7/
improvements after review
move up ie9 check line
Merge pull request #2612 from SergioCrisostomo/2479-setHTML

enable IE8 to set html into style element