Remove config.py

Migrating it into the spicedham class.
Make spicedham a class and bring in _load_config
Convert plugins to use the Spicedham class
Update tests to use Spicedham class
Update test to use Spicedham tests
Remove silly argument
Update report to use Spicedham class
Change default config options
Add sensible defaults when getting configuration
Largely cosmetic changes

* Use 'is_bad' so it's clear that we can classify more than just spam
* Make sure it's floating point division and not integer division
    (It should be float division anyway, but future plugins may not respect
	this)
* Raise an instance not a class
Add docstrings for API, change `is_bad` to `match`

A positive match may be bad, as is the case for spam, or good, as is the case
for usefulness.
Handle case when configs for plugins don't exist