Add route capturing

[rumkin]

1. [x] Add capture method.
2. [x] Add captured slices.

Route#capture()

(part:string, params: object) -> Route

Add capture method to cut read part from the path, put it into captured slices and concat with the base. Also it receives a params object which stores name-value pairs extracted from the path.

route.capture(slice, params)

This method should return new route instance.

Route#captured

[{path: string, params: object}]

List of captured path-params pairs.