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.
I'd be HAPPY to use String, String. The original ```MapConfiguration``` uses a ```Map<String, Object>``` I didn't want to rewrite to much. But I prefer the String, String. We never use anything but strings.