MAHOUT-1489 : initial Mahout spark shell commit

Squashed commit of the following:

commit 0124072b72fcdad9ccded43745c9b1d00e7ea089
Merge: c1a2c8a c9164c1
Author: Dmitriy Lyubimov <dlyubimov@apache.org>
Date:   Tue Apr 22 11:33:17 2014 -0700

    Merge branch 'trunk' into shell

commit c1a2c8a414c015dcdce592b145498fc8b836addf
Merge: a3491f5 a8df05b
Author: Dmitriy Lyubimov <dlyubimov@apache.org>
Date:   Tue Apr 22 11:30:25 2014 -0700

    Merge branch 'trunk' into shell; misc fixes

    Conflicts:
    	bin/mahout

commit a3491f57e77b4b789051cf131bc7fdea73ad3e41
Author: Dmitriy Lyubimov <dlyubimov@apache.org>
Date:   Mon Apr 21 17:39:06 2014 -0700

    -NonLocal

commit bd0c83ebfa66e48f434f0ecc81bf81dd07d27f8c
Merge: ad01add 78c45c4
Author: Dmitriy Lyubimov <dlyubimov@apache.org>
Date:   Mon Apr 21 17:33:18 2014 -0700

    Merge commit '78c45c4c5d96f51e9' into shell

commit ad01add55c1c5a212dabcd727e31dd36162c1fd0
Author: Dmitriy Lyubimov <dlyubimov@apache.org>
Date:   Mon Apr 21 17:30:53 2014 -0700

    Fixing writeDRM problems

commit f9f20e364e4462b6ba0693d11ee939ef5afd43a4
Author: Dmitriy Lyubimov <dlyubimov@apache.org>
Date:   Mon Apr 21 14:58:28 2014 -0700

    writeDRM broken, some unknown closure attributes yank "this", not seeing where and which

commit 7ca93f70ef7313cca251470c41032c08e9e612e2
Author: Dmitriy Lyubimov <dlyubimov@apache.org>
Date:   Mon Apr 21 12:57:40 2014 -0700

    script errors

commit ce5bdfaba160ecb6ee433b4682f62d9e6236e0b6
Author: Dmitriy Lyubimov <dlyubimov@apache.org>
Date:   Thu Apr 17 13:51:35 2014 -0700

    drmFromHDFS() fixes -- load and initiailize classtag evidence correctly.
    TODO: use class evidence from key for saveDRM.

commit aeba609a957b9ef5aac7aa4eba01edb46004116f
Author: Dmitriy Lyubimov <dlyubimov@apache.org>
Date:   Thu Apr 17 11:41:30 2014 -0700

    renaming script extensions

commit 9b02ac2b6aa4ff046a898876f9a8fb23936cd78b
Author: Dmitriy Lyubimov <dlyubimov@apache.org>
Date:   Thu Apr 17 11:17:04 2014 -0700

    build fix

commit 2fbd835c4c4f8fac3ff32d06b9578d436f4bbf09
Author: Dmitriy Lyubimov <dlyubimov@apache.org>
Date:   Wed Apr 16 18:04:47 2014 -0700

    WIP -- unstable

commit cc87347d393709ac0a6ab2adc66200caed07e911
Author: Dmitriy Lyubimov <dlyubimov@apache.org>
Date:   Wed Apr 16 15:27:00 2014 -0700

    removing examples dependencies if running spark shell.

commit 435992aa99090b9a75f3903ac5d10e43e6b49357
Author: Dmitriy Lyubimov <dlyubimov@apache.org>
Date:   Wed Apr 16 14:10:22 2014 -0700

    WIP spark-shell, seems to be working

commit 1f4fd51c2e5e18852d1b30d5a88897e14761d9e8
Author: Dmitriy Lyubimov <dlyubimov@apache.org>
Date:   Wed Apr 16 12:55:17 2014 -0700

    WIP -- implementing "mathout spark-shell"

commit 5922a111405cc66c1d598b123c7d28f456229559
Author: Dmitriy Lyubimov <dlyubimov@apache.org>
Date:   Thu Apr 10 17:53:23 2014 -0700

    First shell  prototype works in local mode

git-svn-id: https://svn.apache.org/repos/asf/mahout/trunk@1589246 13f79535-47bb-0310-9956-ffa450edef68