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 don't believe this is necessary as the default constructor will automatically call `super()`.

```
Note: If a constructor does not explicitly invoke a superclass constructor, the Java compiler
automatically inserts a call to the no-argument constructor of the superclass. If the super
class does not have a no-argument constructor, you will get a compile-time error.
Object does have such a constructor, so if Object is the only superclass, there is no problem.
```
From http://docs.oracle.com/javase/tutorial/java/IandI/super.html