Adding config features

[nucleardreamer]

Overview of what I've added, I know there is a bunch, so feel free to cherry pick:

• Redis auth into config
• Redis key prefix
  • this suffixes the global prefix, for multiple clients using the same server
• Cache on specific header
  • this might be temporary for adding more header cache options
• Cache on specified request methods
  • Filtering out POST and other request methods you wouldn't normally want to cache the response to