Remove old backend module

load_backend has been merged with spicedham/__init__.py
Import load_backend from spicedham

The old spicedham.backend module has been removed
Move load_backend to __init__

1. This way we load both types of files in one place
2. Soon I will wrap this all in a class which will get rid of that nagging
global variable.
Change load_backend to fix bugs and simplify logic

	* I forgot to load the class for non-djangoorm backends (oops).
	* I realized that both branches could share logic.
Modify tests to use the new backends system
Add a list of backends plugins
Make configs pluggable
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
Pass config and backend to plugins

They should have references to the config and the backend, but not to
the whole Spicedham object.