coerce is multiply dispatched
spark coerce
spark test robust to spark absense
hdf5: reinstate DyND coercion on __iter__ and chunks

We avoided this previously because DyND didn't handle NumPy strings well
Now it does.

This allows us to view data stored in HDF5 under different dshapes.
Data is coerced through DyND on its way out.
Merge pull request #370 from mrocklin/hdf5-coercion

hdf5: reinstate DyND coercion on __iter__ and chunks
remove unnecessary itertools import
Skip gzip csv tests on windows py2.x
expr: Join automatically selects all shared columns
test arithmetic column operations

cc @talumbau
Merge pull request #372 from mwiebe/no_gzip_win

Skip gzip csv tests on windows py2.x
Merge pull request #373 from mrocklin/auto-join

expr: Join automatically selects all shared columns
Merge pull request #369 from mrocklin/coerce-rdd

Coerce works on Spark RDDs
into: DataFrame <- ndarray
map.iscolumn heuristics
Added unicde to requirements and docs
Added unicodecsv to conda.yaml
Merge pull request #375 from mrocklin/various-fixes

Various fixes
fix path when running nosetests outside of the test directory
Merge pull request #383 from cpcloud/fix-csv-path

Use the correct path when running nosetests outside of the test's directory
Merge pull request #379 from davclark/master

Added unicde to requirements and docs closes #378