MAHOUT-1300:Support for functional matrix views and some of their concrete implementations.

Squashed commit of the following:

commit 6328f2ef2a79a607c4acfb0ef3f6f2f14720610d
Merge: 7504544 39b207b
Author: Dmitriy Lyubimov <dlyubimov@apache.org>
Date:   Mon Oct 7 12:59:30 2013 -0700

    Merge branch 'trunk' into MAHOUT-1300

commit 7504544f105217c92fe479fe6630e8133e9212dc
Merge: 82b3412 70777c4
Author: Dmitriy Lyubimov <dlyubimov@apache.org>
Date:   Wed Aug 7 23:06:28 2013 -0700

    Merge remote-tracking branch 'apache/trunk' into MAHOUT-1300

commit 82b3412acda7300367261e8610dd49295336ddfd
Author: Dmitriy Lyubimov <dlyubimov@apache.org>
Date:   Tue Jul 30 19:25:25 2013 -0700

    adding default implementation of viewPart to abstract Matrix (probably missing from there.).
    Fixing other things in FunctionalMatrixView.

commit 284adde56d145f22e7e06fa0ed3d684c67dc2783
Author: Dmitriy Lyubimov <dlyubimov@apache.org>
Date:   Tue Jul 30 13:33:58 2013 -0700

    Added Gaussian matrix gen test

commit d0467b80c7cf2770b1ab96c9712cf2956e14cf5f
Author: Dmitriy Lyubimov <dlyubimov@apache.org>
Date:   Tue Jul 30 13:30:15 2013 -0700

    Test and fixes

commit 2a985437a3b02866bc7493b63aa352a872a2b0f2
Author: Dmitriy Lyubimov <dlyubimov@apache.org>
Date:   Tue Jul 30 12:46:03 2013 -0700

    adding Apache 2 license

commit 69c8a532912a411e8abf8af759e25fc3a533925c
Author: Dmitriy Lyubimov <dlyubimov@apache.org>
Date:   Tue Jul 30 12:41:49 2013 -0700

    Initial write-up for MAHOUT-1300

git-svn-id: https://svn.apache.org/repos/asf/mahout/trunk@1530047 13f79535-47bb-0310-9956-ffa450edef68