Prefer to use sumOption to take advantage of algebird optimizations
Make LzoTraits extend TypedSink and LocalTapSource.
Merge pull request #638 from azymnis/lzo_trait_typed_sink

Make LzoTraits extend TypedSink and LocalTapSource.
Merge pull request #637 from twitter/sumOption

Prefer to use sumOption to take advantage of algebird optimizations
Fix the identity sort regression
Beef up tests
Merge pull request #640 from twitter/projection_bug

Fix the identity sort regression