mod_http_oauth2: Namespace the various codes to minimize confusion Both for the programmer and in OAuth flows. While unlikely, it should not be possible to cause weirdness e.g. by typing a client id and authorization code into the device code entry.

This module produces more detailed HTTP logs for Prosodys built-in HTTP
server. The format is similar to that of Apache and go into Prosodys
normal logs at the `info` level.