Summingbird Files

Bring in some of the Config changes from scalding into Summingbird, as a result killing off most of its own configuration code around hadoop properties. - Removing internal config setup from scalding platform: https://github.com/twitter/summingbird/pull/629 - Remove store that no one seems to use and has no tests: https://github.com/twitter/summingbird/pull/630 - Ianoc/optimization changes: https://github.com/twitter/summingbird/pull/628 - Fixes tests: https://github.com/twitter/summingbird/pull/626 - resilient to all stores being complete: https://github.com/twitter/summingbird/pull/627 - Resilient to a store being ahead: https://github.com/twitter/summingbird/pull/625 - move to scala test: https://github.com/twitter/summingbird/pull/621 - Killing off Summingbird Java: https://github.com/twitter/summingbird/pull/624 - Kill summingbird spark: https://github.com/twitter/summingbird/pull/622 - Bumping sbt versions: https://github.com/twitter/summingbird/pull/623 - Fixed erroneous comment in ClientStore's merge description: https://github.com/twitter/summingbird/pull/620