Add support for optional debug parameters
Update debug documentation for clarity and accuracy
Add printFields and printTuple interval support
Update to use builder pattern for options
Merge remote-tracking branch 'upstream/develop' into develop

Conflicts:
	scalding-core/src/main/scala/com/twitter/scalding/RichPipe.scala
Update to take function instead of object
fix reference to pipe
Merge pull request #559 from granthenke/develop

Add support for optional debug parameters