First pass at refactoring.  Notable changes include:

1. Created com.quandl.api.java.query package, to hold classes describing how to query the backing API
2. SimpleQuery replaces and extends the existing functionionality in QuandlConnection's query methods,
   MetadataQuery and MultisetQuery further expand API coverage.
3. Created dedicated factory methods in QuandlConnection, along with some minor cleanup of existing behavior.
4. Created com.quandl.api.java.deprecated package, to hold test classes specifically confirming deprecated
   behavior doesn't regress before being removed.

TODO:
1. Query classes all need JavaDocs.
2. Create mocking behavior for QuandlConnection so we can confirm present and past behavior without making
   remote connections.
Including changes that weren'd properly staged.
Added some JavaDocs