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
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Simply do what you normally do to use Candlepin.

NOTE: I did not update Gutterball.
That's fine. I never get generics correct so I didn't bother :) I'll try what you have above and see how that goes.