Test relabel on Series objects
Implement relabel compute on Series and clean up a bit
Test map with rename
Test failing on renaming a series with multiple names fails
Merge pull request #519 from cpcloud/relabel-series-511

BUG: Allow renaming of a column after mapping
Merge branch 'master' of github.com:ContinuumIO/blaze
into: list <- numpy - better datetime handling

Nanosecond datetimes converted to datetime objects, not Longs
into: DataFrame <- CSV support datetimes with parse_dates
into: exhaustive test - add datetime support
into: exhaustive test with basic compute
into: exhaustive test - refactor data sources
into exhaustive: remove csv from base targets
mongo: tests skip if no mongo server running
python 3 compatibility