Introduce 'giza http' command.

Resources are now broken when accessed via file:// as part of the protocol
agnosticism changes. You must now run 'giza http' and view the generated documentation
at localhost:8090 or whatever port you choose.
The problem is that we don't instantiate the RequestHandler; the server does so for each request, and we don't get to pass in context.

The upshot is that any context needs to be in the class (or its scope), so overriding `BaseHTTPRequestHandler.__init__()` wouldn't help us as far as I see.