Problem with headers in error handler

[nergal]

In current realisation error handler does not consider error type, so http headers in response does not reflect status of processed action.

As example I mean that "not found" action must use 404 status and error action must use 500.

At first, I propose to wrap errors in Response object and extends it by using http status codes (something like Response::setStatus(int $status)).

At second, Bottle_Exception's property "code" shall correlate with status code that current exception must to represent.

[vegaelle]

I have plans for error management. Beside of being wrapped in a Response, an user should be able to overwrite them. I am working on a new handler design to achieve this.