Drop included Sizzle library

I've done some research and apparently there's good enough native support for selectors [1] so I'd say that Sizzle can be removed with minor changes.

Browser round-up:
* As usual, IE is the problem, although in this particular case, it doesn't interfere
  * IE9 has good enough support
  * Previous versions which, for which support is partial or broken, need plug-ins such as ASV who don't use FakeSmile (nor Sizzle) anyway...
* Other browsers with some sort of issues [1] are now probably irrelevant
  * Firefox <3.5
  * Opera <10.0

Benefits:
* Significant reduction of script size
  * 30% code reduction (after minification) - 35.790 bytes versus 25.079 bytes
* Native support is a lot faster [2] anyway
* One less dependency

Requirements:
* Check what kind of selectors are required for SMIL to make sure nothing breaks (I'd welcome pointers and/or some assistance here)

What do you think?

[1] http://caniuse.com/queryselector
[2] http://jsperf.com/yui3-vs-jquery-selector-test-3/44