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
Merge branch 'trunk' of https://github.com/apache/mahout into ann
MAHOUT-1357: InteractionValueEncoder produces wrong traceDictionary entries

git-svn-id: https://svn.apache.org/repos/asf/mahout/trunk@1542279 13f79535-47bb-0310-9956-ffa450edef68
MAHOUT-1292:lucene2seq should validate the 'id' field

git-svn-id: https://svn.apache.org/repos/asf/mahout/trunk@1542553 13f79535-47bb-0310-9956-ffa450edef68
MAHOUT-1292:lucene2seq should validate the 'id' field

git-svn-id: https://svn.apache.org/repos/asf/mahout/trunk@1542596 13f79535-47bb-0310-9956-ffa450edef68
MAHOUT-1343: Replaced deprecated Lucene 3.x API with equivalent Lucene 4.x API.

git-svn-id: https://svn.apache.org/repos/asf/mahout/trunk@1542647 13f79535-47bb-0310-9956-ffa450edef68
MAHOUT-1351:Adding DenseVector support to AbstractCluster

git-svn-id: https://svn.apache.org/repos/asf/mahout/trunk@1542650 13f79535-47bb-0310-9956-ffa450edef68
MAHOUt-1314:StreamingKMeansReducer throws NullPointerException when REDUCE_STREAMING_KMEANS is set to true

git-svn-id: https://svn.apache.org/repos/asf/mahout/trunk@1542944 13f79535-47bb-0310-9956-ffa450edef68
MAHOUT-1358: StreamingKMeansReducer throws IllegalArgumentException when REDUCE_STREAMING_KMEANS is set to true

git-svn-id: https://svn.apache.org/repos/asf/mahout/trunk@1543095 13f79535-47bb-0310-9956-ffa450edef68
MAHOUT-1362: Remove examples/bin/build-reuters.sh

git-svn-id: https://svn.apache.org/repos/asf/mahout/trunk@1543118 13f79535-47bb-0310-9956-ffa450edef68
MAHOUT-1276 job name for ParallelALSFactorizationJob is confusing

git-svn-id: https://svn.apache.org/repos/asf/mahout/trunk@1543963 13f79535-47bb-0310-9956-ffa450edef68
MAHOUT-1292: Minor cleanups

git-svn-id: https://svn.apache.org/repos/asf/mahout/trunk@1544371 13f79535-47bb-0310-9956-ffa450edef68
MAHOUT-1292: Minor cleanup

git-svn-id: https://svn.apache.org/repos/asf/mahout/trunk@1544373 13f79535-47bb-0310-9956-ffa450edef68
MAHOUT-1308: Cannot extend CandidateItemsStrategy due to restricted visibility

git-svn-id: https://svn.apache.org/repos/asf/mahout/trunk@1544380 13f79535-47bb-0310-9956-ffa450edef68
MAHOUT-1308: Cannot extend CandidateItemsStrategy due to restricted visibility

git-svn-id: https://svn.apache.org/repos/asf/mahout/trunk@1544395 13f79535-47bb-0310-9956-ffa450edef68
MAHOUT-1308:Cannot extend CandidateItemsStrategy due to restricted visibility

git-svn-id: https://svn.apache.org/repos/asf/mahout/trunk@1544401 13f79535-47bb-0310-9956-ffa450edef68
Merge branch 'trunk' of https://github.com/apache/mahout into ann
MAHOUT-1317:Clarify some of the messages in Preconditions.checkArgument

git-svn-id: https://svn.apache.org/repos/asf/mahout/trunk@1544673 13f79535-47bb-0310-9956-ffa450edef68
MAHOUT-1361: Online algorithm for computing accurate Quantiles using 1-D clustering

git-svn-id: https://svn.apache.org/repos/asf/mahout/trunk@1544927 13f79535-47bb-0310-9956-ffa450edef68
MAHOUT-1292: Temporary fix to test - testRunInvalidQuery() until we figure out the issue with the MR version of the code.

git-svn-id: https://svn.apache.org/repos/asf/mahout/trunk@1544928 13f79535-47bb-0310-9956-ffa450edef68