Config unification

Replace Candlepin's Config class with Configuration from common. No more ```new Config()``` in mainline code, rely on injection of Configuration from Guice.

TEST
---------
Simply do what you normally do to use Candlepin.

NOTE: I did not update Gutterball.
I haven't the foggiest idea why I went with Object.  I think I was vaguely anticipating that people might want to add actual data structures to a MapConfiguration since that configuration is in-memory only.  E.g. `c.setProperty('x', new X())`

I guess I would favor then having MapConfiguration use generics and then PropertiesFileConfiguration can have

```
private MapConfiguration backingMap = new MapConfiguration<String>();
```

unless there are a lot of places where people are using MapConfiguration directly.  If that's the case, then `<String, String>` seems like the way to go.