fix `sanitize` mode
comment tags are dangerous on IE
clean code
clean code and change the behavior for raw code blocks of `sanitize` mode
Now in `sanitize` mode, raw code blocks without highlight function will become normal code blocks, instead of being stripped away.
fix filters of URI and CSS
replace suspicious code with string "XSS" to avoid recursion replacement tricks
fix the lexing of definitions of images and figures
ref: http://html5sec.org/#46
fix URI filter
fix: make sure the enumeration order for object properties is correct
update
update