Advanced WSGI API

HTTP routing and implements will be in the same place. This idea was
inspired from Flask and Bottle of Python and JAX-RS of Java. This
modification keeps backward compatibility.

Signed-off-by: Satoshi Kobayashi <satoshi-k@stratosphere.co.jp>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>