Specifically, allow definition of a set of settings as module in the
configuration file, and the ability to use these settings by setting the
`module` URL parameter to the respective module name when scraping.
THIS COMMIT CHANGES THE CONFIG FORMAT IN A NON-BACKWARDS-COMPATIBLE WAY!
Based on this, the following "side effects" are noteworthy:
- the exporter no longer requires a config file
- the IPMI "privilege level" can be set in the config file
- collectors can be enabled/disabled in the config file
- anonymous IPMI access is now theoretically possible
- there are now two example configurations (local & remote)
This fixes#10 by allowing to set the privilege level.
