MAHOUT-1561, MAHOUT-1568, MAHOUT-1569 text-delimited Spark readers and writers with drivers and a CLI for 'spark-itemsimilarity' closes apache/mahout#22
disabled ItemSimilarity test until we can work out how to run them without MAHOUT_HOME and SPARK_HOME being set
MAHOUT-1541, MAHOUT-1568, MAHOUT-1569 fixed a build test problem, drivers have an option new to not search for MAHOUT_HOME and SPARK_HOME
Merge branch 'master' of https://git-wip-us.apache.org/repos/asf/mahout
MAHOUT-1541 backed out compatability with legacy Item Similarity, now outputs raw LLR scores
MAHOUT-1541, MAHOUT-1568, added option to ItemSimilarityDriver to allow output that is directly search engine indexable, also some default schema's for input and output of TDF tuples and DRMs
MAHOUT-1583: cbind() operator for Scala DRMs
This closes apache/mahout#20

Squashed commit of the following:

commit 1baf3fcebf2cd49eb6487afe4eaed689653a3562
Merge: 41f0671 9bfb767
Author: Dmitriy Lyubimov <dlyubimov@apache.org>
Date:   Mon Jul 7 12:32:34 2014 -0700

    Merge branch 'master' into MAHOUT-1583

commit 41f0671c9ccca81883475437fe18056563c1f8ac
Author: Dmitriy Lyubimov <dlyubimov@apache.org>
Date:   Mon Jul 7 12:27:26 2014 -0700

    Adding assignment time comparison test

commit 6e115c87639ffb111b2e089d7ecdf0eaeecbb02b
Author: Dmitriy Lyubimov <dlyubimov@apache.org>
Date:   Mon Jun 16 18:42:42 2014 -0700

    + Licenses.

commit d3e905b5a92735822efe717f8b7a57c80bc56478
Author: Dmitriy Lyubimov <dlyubimov@apache.org>
Date:   Mon Jun 16 18:09:59 2014 -0700

    initial writeup
MAHOUT-1529: third collection of various edits against private branch

Squashed commit of the following:

commit 4328aae135bc56c02b944c21af2cfd6629b262bf
Author: Dmitriy Lyubimov <dlyubimov@apache.org>
Date:   Mon Jul 7 13:13:26 2014 -0700

    Various 1529-related stuff collected from private fork
MAHOUT-1529 (d): moving core engine-independent tests logic to math-scala, spark module running them.
Source: dlyubimov/MAHOUT-1529d
This closes apache/mahout#28.

Squashed commit of the following:

commit 8d693b02e474ca1380c0e1cfa262ec4a47afeeae
Author: Dmitriy Lyubimov <dlyubimov@apache.org>
Date:   Mon Jul 14 13:03:13 2014 -0700

    minor style

commit f568736a35a8c76c6eb70694ce9feee09ff845dc
Author: Dmitriy Lyubimov <dlyubimov@apache.org>
Date:   Mon Jul 14 12:57:19 2014 -0700

    + license

commit d47e2dca693c147e6978a6c5e1fe42c1ab73ece3
Author: Dmitriy Lyubimov <dlyubimov@apache.org>
Date:   Mon Jul 14 12:55:36 2014 -0700

    + license

commit 61e6268d261c875781d430ca7861e0b345f485c3
Author: Dmitriy Lyubimov <dlyubimov@apache.org>
Date:   Fri Jul 11 11:31:44 2014 -0700

    style

commit c2406654c3fc7326b87848a23933cd4031a2c9a9
Author: Dmitriy Lyubimov <dlyubimov@apache.org>
Date:   Fri Jul 11 11:27:53 2014 -0700

    Initial test rearrangement. Pushing engine-independent logic to math-scala. Some renames.
NOJIRA: distributed context property must really be public for engine-agnostic consumers
MAHOUT-1529(e): Move dense/sparse matrix test in mapBlock into spark (Anand Avati via dlyubimov)
All math-scala, spark tests are  passing.
this closes apache/mahout#29

Squashed commit of the following:

commit 1e3cdb68198636c9f38f2d41d782d12edba7a2f7
Author: Anand Avati <avati@redhat.com>
Date:   Mon Jul 14 17:20:09 2014 -0700

    MAHOUT-1529: Move dense/sparse matrix test in mapBlock into spark/

    In h2o engine, the Matrix provided to mapBlock() is an instance of
    "H2OBlockMatrix extends AbstractMatrix", and neither a DenseMatrix
    nor SparseMatrix. H2OBlockMatrix is a 0-copy virtual Matrix exposing
    just the partition's data (created at almost no expense), and creates
    a copy-on-write Matrix only if modified by the blockmapfunction.

    So these two tests are failing with h2obindings. Hence moving these two
    tests into spark module.

    Signed-off-by: Anand Avati <avati@redhat.com>
MAHOUT-1595: MatrixVectorView - implement a proper iterateNonZero() (Anand Avati via dlyubimov)
this closes apache/mahout#25

Squashed commit of the following:

commit eb2aa35da282b8955907fcd1ef358e825a100e95
Author: Anand Avati <avati@redhat.com>
Date:   Wed Jul 9 14:29:13 2014 -0700

    MAHOUT-1595: MatrixVectorView - implement a proper iterateNonZero()

    Previous implementation was broken as it was just calling iterator()

    Signed-off-by: Anand Avati <avati@redhat.com>
MAHOUT-1597: A + 1.0 (element-wise scala operation) gives wrong result if rdd is missing rows, Spark side (dlyubimov)
This closes apache/mahout#33

Squashed commit of the following:

commit 9038b2c248ec163e0ff85dd37cb109345b3bbb9d
Author: Dmitriy Lyubimov <dlyubimov@apache.org>
Date:   Mon Jul 28 10:22:30 2014 -0700

    in-place performance enhancement at the risk of side-effects, for now

commit 35c873cceeda87b7b212677bffc0a21877932deb
Author: Dmitriy Lyubimov <dlyubimov@apache.org>
Date:   Tue Jul 22 15:34:00 2014 -0700

    CBind test tweak

commit 005aeccd353faeb59f2ddb2003f393a603978edb
Author: Dmitriy Lyubimov <dlyubimov@apache.org>
Date:   Tue Jul 22 15:33:18 2014 -0700

    Cbind test

commit 57f669a7d50097a5a816ce13ca8230f6c6742b65
Author: Dmitriy Lyubimov <dlyubimov@apache.org>
Date:   Tue Jul 22 14:57:57 2014 -0700

    Also fixing `A ew B` with missing rows operands

commit 2063c5ccaf88bf31d7f5c1dd3d1650925c4dfd58
Author: Dmitriy Lyubimov <dlyubimov@apache.org>
Date:   Tue Jul 22 14:12:56 2014 -0700

    style

commit 5d8e1407a7ea2535ae6d00701ed4f60390c1b30e
Author: Dmitriy Lyubimov <dlyubimov@apache.org>
Date:   Tue Jul 22 14:09:11 2014 -0700

    Orientation changing unary ops cannot produce missing rows

commit c9ac3be81ed464ccc4d440b8187e15efa9a21193
Author: Dmitriy Lyubimov <dlyubimov@apache.org>
Date:   Tue Jul 22 14:03:25 2014 -0700

    Tests, passing .

commit 1ff376b2ddd1bcbe61f896d14e27d7a413e7313c
Author: Dmitriy Lyubimov <dlyubimov@apache.org>
Date:   Tue Jul 22 13:23:14 2014 -0700

    Code up for lazy int-keyed missing rows fix

commit 746b3ddc6c0e7e8bb89ce591c32ba1b70ec688e6
Author: Dmitriy Lyubimov <dlyubimov@apache.org>
Date:   Tue Jul 22 11:25:57 2014 -0700

    WIP

commit 45642b65f3f1620a4e2187af4b2b54e26ce1c42e
Author: Dmitriy Lyubimov <dlyubimov@apache.org>
Date:   Mon Jul 21 18:19:37 2014 -0700

    WIP
closes apache/mahout#27, nonsensical PR
MAHOUT-1596: implement rbind() operator

This closes apache/mahout#30

Conflicts:
	math-scala/src/test/scala/org/apache/mahout/math/drm/RLikeDrmOpsSuiteBase.scala
NOJIRA: renaming distributed ALS `als` -> `dals` to follow convention with other decomposition notations.
(NOJIRA) minor test style
NOJIRA: more parameter naming conventions (style)
(NOJIRA) style, spacing
MAHOUT-1597: A + 1.0 (fixes)