slamdata/slamengine — pull request #161 by jdegoes (2014-08-07 17:55:30+00:00)
Title: Part of #157

1. Delete PipelineBuilder.fromInit and replace with less expressive method on PipelineBuilder, misc code cleanup
2. Don't use default args for PipelineBuilder.groupBy and add bogus merging method to merge grouping sets