Configuration file for the broker

[bestchai]

The broker will need to be parameterized in a number of ways:

• IP/port for subscribers (required)
• IP/port for publishers (required)
• file for file-subscriber (optional)
• token for authenticating subscribers (optional)
• token for authenticating publishers (optional)
• IP origin authentication option (optional)

Instead of architecting a command line madness, it would be great to push these into a config file and use an existing config file library for reading these options.