Parsoid/Todo:HTML5

Tracked in 39161.

= Possible bugs =
 * It appears that the html5 builder strips comments from inline style attributes. A parsed token with "/* insecure input */" value for the style key comes out as style="" when HTML is generated.  To investigate if this is a bug in HTML5, or if the HTML5 spec dictates this.  In either case, we need a fix for this so sanitized attributes can get round-tripped properly.  If a bug in HTML5, we report a bug @ https://github.com/aredridel/html5.  If not, we fix the sanitizer code to not emit inline comments. Try the following command to test:
 * echo 'foo ' | node parse.js | sed 's/&amp;quot;/"/g;'