Mahout build

[Pat Ferrel <pa...@occamsmachete.com>]

We need to decide how the Mahout build and release is to be structured because some work is required to accommodate Spark and H2O. The addition of Spark code is not complete—build-wise. We need to add dependency jars to the classpath and the release tar has no Spark or H2O classes included at all. This is complicated by the fact that the structure of the release tar is different than the one created building from source. These IMO should be unified so the release is a subset of build-from-source (the release tar has a mahout/lib dir, build-from-source does not).

If we are going to have another release we have to address these issues and I think it will mean a fair bit of maven hacking.