Add support for optional debug parameters
Update debug documentation for clarity and accuracy
Add printFields and printTuple interval support
sumByLocalKeys, Counters and Task Numbers
enforce version 0.6.2 of sbt-git to work around https://github.com/sbt/sbt-git/issues/19
Merge pull request #695 from fs111/develop

enforce version 0.6.2 of sbt-git
Update README
Fix enumeration
Merge pull request #698 from twitter/readme-irc

Update README
Adds head and sortedTake to KeyedList
Split JsonLine source out of FileSource.
Split JsonLineTest.
Merge pull request #703 from twitter/klin_json_sep

Make Json support a separate module
Pull out scalding-json as a separate module.
Add scalding-json to project/Build.
Added Test for CascadingJob Through Tool.main
Fix CascadeJob NPE
- Overrode validate to iterate over def jobs to call validate on each
  job.
Clean build dependencies.
Remove jackson dependency from scalding-core.
Generate simple json JobStats in Tool.