Update Sizzle to 1.9.1

Tagged: https://github.com/jquery/jquery/tree/1.9.1 ([jQuery 1.9.1](https://github.com/jquery/jquery/tree/1.9.1/src) uses Sizzle [@c0d9bad](https://github.com/jquery/sizzle/tree/c0d9badeb5dac649d0ba7824efaebbe4155369b5)).