expr: add path-split function
expr: Split function to chunk expressions
expr: split distinct operations, fix split
summary string printing
expr: split on summaries
wip: split expr on by, expose error on summary
expr: ensure that summary.child is not a reduction
expr: summary child must be tableexpr
ensure that path-split on summary of one reduction returns summary
py26: remove dict comprehensions
split on embarassing computations
Merge pull request #636 from mrocklin/split

Split