Matcher specificity

The correct element wrapper gets selected by the specificity of the CSS selector.
If the matcher isn't a CSS selector and matches the node, that one will be selected because we can't calculate the specificity of a function.

Also @subtleGradient mentioned that the specificity module should be in Slick. I added it here anyway because the AMD transformation of Slick is still WIP and I couldn't find the right place in that branch yet. To keep pace we can just have it here, once Slick(/Parser) is converted it'll be easy to move it anyway.