[SPARK-2434][MLlib]: Warning messages that point users to original MLlib implementations added to Examples

[SPARK-2434][MLlib]: Warning messages that refer users to the original MLlib implementations of some popular example machine learning algorithms added both in the comments and the code. The following examples have been modified:
Scala:
* LocalALS
* LocalFileLR
* LocalKMeans
* LocalLP
* SparkALS
* SparkHdfsLR
* SparkKMeans
* SparkLR
Python:
 * kmeans.py
 * als.py
 * logistic_regression.py

Author: Burak <brkyvz@gmail.com>

Closes #1515 from brkyvz/SPARK-2434 and squashes the following commits:

7505da9 [Burak] [SPARK-2434][MLlib]: Warning messages added, scalastyle errors fixed, and added missing punctuation
b96b522 [Burak] [SPARK-2434][MLlib]: Warning messages added and scalastyle errors fixed
4762f39 [Burak] [SPARK-2434]: Warning messages added
17d3d83 [Burak] SPARK-2434: Added warning messages to the naive implementations of the example algorithms
2cb5301 [Burak] SPARK-2434: Warning messages redirecting to original implementaions added.
[SPARK-2561][SQL] Fix apply schema

We need to use the analyzed attributes otherwise we end up with a tree that will never resolve.

Author: Michael Armbrust <michael@databricks.com>

Closes #1470 from marmbrus/fixApplySchema and squashes the following commits:

f968195 [Michael Armbrust] Use analyzed attributes when applying the schema.
4969015 [Michael Armbrust] Add test case.
[SPARK-2086] Improve output of toDebugString to make shuffle boundaries more clear

Changes RDD.toDebugString() to show hierarchy and shuffle transformations more clearly

New output:

```
(3) FlatMappedValuesRDD[325] at apply at Transformer.scala:22
 |  MappedValuesRDD[324] at apply at Transformer.scala:22
 |  CoGroupedRDD[323] at apply at Transformer.scala:22
 +-(5) MappedRDD[320] at apply at Transformer.scala:22
 |  |  MappedRDD[319] at apply at Transformer.scala:22
 |  |  MappedValuesRDD[318] at apply at Transformer.scala:22
 |  |  MapPartitionsRDD[317] at apply at Transformer.scala:22
 |  |  ShuffledRDD[316] at apply at Transformer.scala:22
 |  +-(10) MappedRDD[315] at apply at Transformer.scala:22
 |     |   ParallelCollectionRDD[314] at apply at Transformer.scala:22
 +-(100) MappedRDD[322] at apply at Transformer.scala:22
     |   ParallelCollectionRDD[321] at apply at Transformer.scala:22
```

Author: Gregory Owen <greowen@gmail.com>

Closes #1364 from GregOwen/to-debug-string and squashes the following commits:

08f5c78 [Gregory Owen] toDebugString: prettier debug printing to show shuffles and joins more clearly
1603f7b [Gregory Owen] toDebugString: prettier debug printing to show shuffles and joins more clearly
[SPARK-2470] PEP8 fixes to PySpark

This pull request aims to resolve all outstanding PEP8 violations in PySpark.

Author: Nicholas Chammas <nicholas.chammas@gmail.com>
Author: nchammas <nicholas.chammas@gmail.com>

Closes #1505 from nchammas/master and squashes the following commits:

98171af [Nicholas Chammas] [SPARK-2470] revert PEP 8 fixes to cloudpickle
cba7768 [Nicholas Chammas] [SPARK-2470] wrap expression list in parentheses
e178dbe [Nicholas Chammas] [SPARK-2470] style - change position of line break
9127d2b [Nicholas Chammas] [SPARK-2470] wrap expression lists in parentheses
22132a4 [Nicholas Chammas] [SPARK-2470] wrap conditionals in parentheses
24639bc [Nicholas Chammas] [SPARK-2470] fix whitespace for doctest
7d557b7 [Nicholas Chammas] [SPARK-2470] PEP8 fixes to tests.py
8f8e4c0 [Nicholas Chammas] [SPARK-2470] PEP8 fixes to storagelevel.py
b3b96cf [Nicholas Chammas] [SPARK-2470] PEP8 fixes to statcounter.py
d644477 [Nicholas Chammas] [SPARK-2470] PEP8 fixes to worker.py
aa3a7b6 [Nicholas Chammas] [SPARK-2470] PEP8 fixes to sql.py
1916859 [Nicholas Chammas] [SPARK-2470] PEP8 fixes to shell.py
95d1d95 [Nicholas Chammas] [SPARK-2470] PEP8 fixes to serializers.py
a0fec2e [Nicholas Chammas] [SPARK-2470] PEP8 fixes to mllib
c85e1e5 [Nicholas Chammas] [SPARK-2470] PEP8 fixes to join.py
d14f2f1 [Nicholas Chammas] [SPARK-2470] PEP8 fixes to __init__.py
81fcb20 [Nicholas Chammas] [SPARK-2470] PEP8 fixes to resultiterable.py
1bde265 [Nicholas Chammas] [SPARK-2470] PEP8 fixes to java_gateway.py
7fc849c [Nicholas Chammas] [SPARK-2470] PEP8 fixes to daemon.py
ca2d28b [Nicholas Chammas] [SPARK-2470] PEP8 fixes to context.py
f4e0039 [Nicholas Chammas] [SPARK-2470] PEP8 fixes to conf.py
a6d5e4b [Nicholas Chammas] [SPARK-2470] PEP8 fixes to cloudpickle.py
f0a7ebf [Nicholas Chammas] [SPARK-2470] PEP8 fixes to rddsampler.py
4dd148f [nchammas] Merge pull request #5 from apache/master
f7e4581 [Nicholas Chammas] unrelated pep8 fix
a36eed0 [Nicholas Chammas] name ec2 instances and security groups consistently
de7292a [nchammas] Merge pull request #4 from apache/master
2e4fe00 [nchammas] Merge pull request #3 from apache/master
89fde08 [nchammas] Merge pull request #2 from apache/master
69f6e22 [Nicholas Chammas] PEP8 fixes
2627247 [Nicholas Chammas] broke up lines before they hit 100 chars
6544b7e [Nicholas Chammas] [SPARK-2065] give launched instances names
69da6cf [nchammas] Merge pull request #1 from apache/master
[SPARK-2452] Create a new valid for each  instead of using lineId.

Author: Prashant Sharma <prashant@apache.org>

Closes #1441 from ScrapCodes/SPARK-2452/multi-statement and squashes the following commits:

26c5c72 [Prashant Sharma] Added a test case.
7e8d28d [Prashant Sharma] SPARK-2452, create a new valid for each  instead of using lineId, because Line ids can be same sometimes.
[SPARK-2612] [mllib] Fix data skew in ALS

Author: peng.zhang <peng.zhang@xiaomi.com>

Closes #1521 from renozhang/fix-als and squashes the following commits:

b5727a4 [peng.zhang] Remove no need argument
1a4f7a0 [peng.zhang] Fix data skew in ALS