Redesign a 404 page.

1. redesign a 404 page.
2. add duplicated pattern validation in mux.
3. makeRouter --> MakeRouter.
Fix router match bug.

1. fix router match bug.
2. check mux match procedure.
Fix default 404 handler bug.

1. fix a variable name with spell error.
2. fix default not found handler's type issue, make proc's `NotFound()`
method work.
Merge pull request #9 from ggicci/reconstruction

Reconstruction