support absolute paths in the uri parser
implement a basic route mechanism
distinguish between 404 and 405 when searching for routes
reject absolute uris with the wrong host in requests
handle the Host header
add missing uri tests
simplify http_uri_parse()
refactor struct http_msg
support the host:port format for the Host header
correctly handle IPv6 addresses in the Host header

An IPv6 numeric address must be enclosed by brackets.
implement rfc 2732 (IPv6 addresses in URIs)
read and store named parameters
skip header processing for tests

If we do not skip header processing, all tests will fail for missing the Host
header.