EXP-36. Implements a generic AvroRecord class.

Reviewed by: robertchu
EXP-41. Fixes express script with new bento packaging.

Updates express script to account for distribution-specific packaging of
KijiSchema and KijiMR libjars.

Reviewed by: kiyan
EXP-29. Add Implicits containing implicit conversions.

This commit adds repl.Implicits.scala, which contains implicit
conversions necessary for authoring Scalding flows. This will be
useful in providing a REPL environment for authoring pipelines to the
user.

Reviewed by: kiyan