Start work on scalding-lingual support.

Lingual has some nice features that would be nice to have for some small adhoc jobs and especially with the Scalding REPL.  These changes do not contain the repl code yet(coming in a future pull request) but attempt make lingual a bit easier to use with Scalding libraries and allow for scalding code to still be written and run with a Lingual job.

This code also does not support nested functions yet in queries like thrift.  Should be technically possible based on conversations with the Lingual team.


Not much, would there be a better place for these extensions to live?  The lingualTap function is mostly a work around because Scalding has a sealed trait if I remember correctly around where a similar operation is done during a Source.read.