add two failing sql reduction tests
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
Whittle down where this is actually happening
Pass encoding where possible
resource split refactored out to single high-priority function
add impala sqlalchemy resource function
Merge pull request #640 from cpcloud/fix-csv-encoding

Fix OS X Encoding test
py26: remove dict comprehensions
fix syntax error in test
Merge pull request #646 from mrocklin/impyla-resource

Impyla resource dispatched method
Merge branch 'master' into fix-sql-reductions
columnwise on complex selection