Made interface of uri push_back_string free.
Added uri_interface.
Using class uri for request_uri.
A request_uri is everytime HTTP.
Made media type copyable.
Simplified response_parser::reason_phrase().
Refactored media_type::parameter().
Added media_type_interface. Refacted type naming.
Removed is_valid_uri_scheme_character and is_valid_url_character.
Improved coverage.
Added wider access to data_content_type and accept header.
Implemented function uri::set_host.
Using a default port for http in an uri.
Implemented member functions to overwrite userinfo and port of an URI.
Implemented host header.
Fixed deadlock, when setting userinfo or host.
Added unit test for host header.
Fixed constness of listener_socket::accept().
Removed unused function.
Added virtual destructors to uri and media type interfaces.