Eclipse classpaths for daffodil-io module need fixing

daffodil-io needs to include src/main/scala, but exclude src/test/scala not just from the eclipse source directories but from the entire eclipse project.

Otherwise searching for things found in daffodil-io-unittest will always hit twice. Once in daffodil-io, and again in daffodil-io-unittest. This can be quite confusing.