Mixin module. It provides the follow functionality groups:
- Access to CGI environment variables as methods. See documentation to the CGI class for a list of these variables.
- Access to cookies, including the cookies attribute.
- Access to parameters, including the params attribute, and overloading
- to perform parameter value lookup by key.
- The initialize_query method, for initialising the above mechanisms, handling multipart forms, and allowing the class to be used in "offline" mode.