remove hard coded spill threshold default
Attempted fix for https://github.com/nathanmarz/cascalog/issues/207
set threshold to 0 if not set via :spill-threshold to ensure proper handling by cascading
Merge pull request #212 from sorenmacbeth/develop

properly handle spill-threshold
Adds `hfs-wholefile` to `cascalog-more-taps`.
This work has originally been done by Sam Ritchie for reddmetrics/forma-clj.
Merge pull request #213 from ticking/hfs-wholefile

Adds `hfs-wholefile` to `cascalog-more-taps`.
Merge pull request #211 from funkenblatt/fix-207

Attempted fix for https://github.com/nathanmarz/cascalog/issues/207
used latest stable release of cascading: 2.5.1
Merge pull request #218 from fs111/develop

used latest stable release of cascading: 2.5.1
Preserve order for grouping fields.
Make it even simpler.
Merge pull request #220 from funkenblatt/fix-grouping

Preserve order for grouping fields.
update codox ver to 0.6.6
Merge pull request #221 from Quantisan/develop

update codox ver to 0.6.6
CascalogTap should implement ISelectFields
Merge pull request #222 from sorenmacbeth/develop

CascalogTap should implement ISelectFields
fixes #217
Merge pull request #223 from sorenmacbeth/develop

fixes #217
Add support for supplying an open taps threshold argument to template tap.