test map behavior
pandas: count on dataframes
Merge branch 'optimize-and-scope'
numpy: count on recarrays
expr: split std/var/mean guard against integer division
bcolz: compute_down with split
expr: split nelements
numpy: nelements supports keepdims
expr: summary doesn't fail on value with multiple children
expr: more tests for expr split
expr: split like
expr: split on keepdims propagates keepdims
expr: split(summary) with nunique raises NotImplementedError
compute: test_comprehensive by uses summary syntax
bcolz: remove compute_up recipes.  Replaced by split
Merge branch 'master' into bcolz-split
expr: lean projection on distinct
expr: lean projection on like
compute: pre_compute is given top expression, not leaf
bcolz: pre_compute