MAHOUT-1297: initial write-up of in-core mahout scala DSL

Squashed commit of the following:

commit 9fff9c190f908133d288512c1ae1deef617a0845
Merge: 62aa138 ebfb3a3
Author: Dmitriy Lyubimov <dlyubimov@apache.org>
Date:   Mon Nov 11 16:19:27 2013 -0800

    Merge branch 'trunk' into MAHOUT-1297

commit 62aa1387067d33b1d9253e093dea59f7393308a0
Author: Dmitriy Lyubimov <dlyubimov@apache.org>
Date:   Tue Nov 5 14:35:59 2013 -0800

    Fixing license headers.

commit dd921c4261af0d8d48437b166a964373a30d6f85
Author: Dmitriy Lyubimov <dlyubimov@apache.org>
Date:   Tue Nov 5 14:28:42 2013 -0800

    cutting off MAHOUT-1297 from the head of scala-dev branch using tree merge for the math-scala subtree.

git-svn-id: https://svn.apache.org/repos/asf/mahout/trunk@1540905 13f79535-47bb-0310-9956-ffa450edef68