wip: failing test for split(mean)
test map behavior
expr: split mean
Merge branch 'master' of github.com:ContinuumIO/blaze into split-mean
pandas: compute summary on series
expr: summary splits containing summaries flatten
expr: split variance and standard deviation
expr: more complex split test
expr: lean projection works on simple elemwise case
bcolz uses available_memory
expr: avoid axis validation in Reduction constructor

Validation is good so this commit is something of a regression.

Expressions shouldn't encode logic in their constructors.  This logic should be
moved out to a separate function.  Along these lines, sum should probably
become Sum with sum a function, etc..
Merge branch 'split-mean' of github.com:mrocklin/blaze into split-mean
fix std/var definition
compute: traversal updates scope after optimize calls
compute: clean up try-except and if-else blocks
missing import in chunks
activate csv to pandas pre_compute by default
Merge pull request #836 from mrocklin/split-mean

Split more reductions
pandas: count on dataframes
Merge branch 'optimize-and-scope'