SPARK-1862: Support for MapR in the Maven build.

Author: Patrick Wendell <pwendell@gmail.com>

Closes #803 from pwendell/mapr-support and squashes the following commits:

8df60e4 [Patrick Wendell] SPARK-1862: Support for MapR in the Maven build.
HOTFIX: Duplication of hbase version
bugfix: overflow of graphx Edge compare function

Author: Zhen Peng <zhenpeng01@baidu.com>

Closes #769 from zhpengg/bugfix-graphx-edge-compare and squashes the following commits:

8a978ff [Zhen Peng] add ut for graphx Edge.lexicographicOrdering.compare
413c258 [Zhen Peng] there maybe a overflow for two Long's substraction
[SQL] Implement between in hql

Author: Michael Armbrust <michael@databricks.com>

Closes #804 from marmbrus/between and squashes the following commits:

ae24672 [Michael Armbrust] add golden answer.
d9997ef [Michael Armbrust] Implement between in hql.
9bd4433 [Michael Armbrust] Better error on parse failures.
SPARK-1487 [SQL] Support record filtering via predicate pushdown in Parquet

Simple filter predicates such as LessThan, GreaterThan, etc., where one side is a literal and the other one a NamedExpression are now pushed down to the underlying ParquetTableScan. Here are some results for a microbenchmark with a simple schema of six fields of different types where most records failed the test:

             | Uncompressed  | Compressed
-------------| ------------- | -------------
File size  |     10 GB  | 2 GB
Speedup |      2         | 1.8

Since mileage may vary I added a new option to SparkConf:

`org.apache.spark.sql.parquet.filter.pushdown`

Default value would be `true` and setting it to `false` disables the pushdown. When most rows are expected to pass the filter or when there are few fields performance can be better when pushdown is disabled. The default should fit situations with a reasonable number of (possibly nested) fields where not too many records on average pass the filter.

Because of an issue with Parquet ([see here](https://github.com/Parquet/parquet-mr/issues/371])) currently only predicates on non-nullable attributes are pushed down. If one would know that for a given table no optional fields have missing values one could also allow overriding this.

Author: Andre Schumacher <andre.schumacher@iki.fi>

Closes #511 from AndreSchumacher/parquet_filter and squashes the following commits:

16bfe83 [Andre Schumacher] Removing leftovers from merge during rebase
7b304ca [Andre Schumacher] Fixing formatting
c36d5cb [Andre Schumacher] Scalastyle
3da98db [Andre Schumacher] Second round of review feedback
7a78265 [Andre Schumacher] Fixing broken formatting in ParquetFilter
a86553b [Andre Schumacher] First round of code review feedback
b0f7806 [Andre Schumacher] Optimizing imports in ParquetTestData
85fea2d [Andre Schumacher] Adding SparkConf setting to disable filter predicate pushdown
f0ad3cf [Andre Schumacher] Undoing changes not needed for this PR
210e9cb [Andre Schumacher] Adding disjunctive filter predicates
a93a588 [Andre Schumacher] Adding unit test for filtering
6d22666 [Andre Schumacher] Extending ParquetFilters
93e8192 [Andre Schumacher] First commit Parquet record filtering
Tweaks to Mesos docs

- Mention Apache downloads first
- Shorten some wording

Author: Matei Zaharia <matei@databricks.com>

Closes #806 from mateiz/doc-update and squashes the following commits:

d9345cd [Matei Zaharia] typo
a179f8d [Matei Zaharia] Tweaks to Mesos docs
SPARK-1864 Look in spark conf instead of system properties when propagating configuration to executors.

Author: Michael Armbrust <michael@databricks.com>

Closes #808 from marmbrus/confClasspath and squashes the following commits:

4c31d57 [Michael Armbrust] Look in spark conf instead of system properties when propagating configuration to executors.
Version bump of spark-ec2 scripts

This will allow us to change things in spark-ec2 related to the 1.0 release.

Author: Patrick Wendell <pwendell@gmail.com>

Closes #809 from pwendell/spark-ec2 and squashes the following commits:

59117fb [Patrick Wendell] Version bump of spark-ec2 scripts
[SPARK-1808] Route bin/pyspark through Spark submit

**Problem.** For `bin/pyspark`, there is currently no other way to specify Spark configuration properties other than through `SPARK_JAVA_OPTS` in `conf/spark-env.sh`. However, this mechanism is supposedly deprecated. Instead, it needs to pick up configurations explicitly specified in `conf/spark-defaults.conf`.

**Solution.** Have `bin/pyspark` invoke `bin/spark-submit`, like all of its counterparts in Scala land (i.e. `bin/spark-shell`, `bin/run-example`). This has the additional benefit of making the invocation of all the user facing Spark scripts consistent.

**Details.** `bin/pyspark` inherently handles two cases: (1) running python applications and (2) running the python shell. For (1), Spark submit already handles running python applications. For cases in which `bin/pyspark` is given a python file, we can simply call pass the file directly to Spark submit and let it handle the rest.

For case (2), `bin/pyspark` starts a python process as before, which launches the JVM as a sub-process. The existing code already provides a code path to do this. All we needed to change is to use `bin/spark-submit` instead of `spark-class` to launch the JVM. This requires modifications to Spark submit to handle the pyspark shell as a special case.

This has been tested locally (OSX and Windows 7), on a standalone cluster, and on a YARN cluster. Running IPython also works as before, except now it takes in Spark submit arguments too.

Author: Andrew Or <andrewor14@gmail.com>

Closes #799 from andrewor14/pyspark-submit and squashes the following commits:

bf37e36 [Andrew Or] Minor changes
01066fa [Andrew Or] bin/pyspark for Windows
c8cb3bf [Andrew Or] Handle perverse app names (with escaped quotes)
1866f85 [Andrew Or] Windows is not cooperating
456d844 [Andrew Or] Guard against shlex hanging if PYSPARK_SUBMIT_ARGS is not set
7eebda8 [Andrew Or] Merge branch 'master' of github.com:apache/spark into pyspark-submit
b7ba0d8 [Andrew Or] Address a few comments (minor)
06eb138 [Andrew Or] Use shlex instead of writing our own parser
05879fa [Andrew Or] Merge branch 'master' of github.com:apache/spark into pyspark-submit
a823661 [Andrew Or] Fix --die-on-broken-pipe not propagated properly
6fba412 [Andrew Or] Deal with quotes + address various comments
fe4c8a7 [Andrew Or] Update --help for bin/pyspark
afe47bf [Andrew Or] Fix spark shell
f04aaa4 [Andrew Or] Merge branch 'master' of github.com:apache/spark into pyspark-submit
a371d26 [Andrew Or] Route bin/pyspark through Spark submit
[SPARK-1824] Remove <master> from Python examples

A recent PR (#552) fixed this for all Scala / Java examples. We need to do it for python too.

Note that this blocks on #799, which makes `bin/pyspark` go through Spark submit. With only the changes in this PR, the only way to run these examples is through Spark submit. Once #799 goes in, you can use `bin/pyspark` to run them too. For example,

```
bin/pyspark examples/src/main/python/pi.py 100 --master local-cluster[4,1,512]
```

Author: Andrew Or <andrewor14@gmail.com>

Closes #802 from andrewor14/python-examples and squashes the following commits:

cf50b9f [Andrew Or] De-indent python comments (minor)
50f80b1 [Andrew Or] Remove pyFiles from SparkContext construction
c362f69 [Andrew Or] Update docs to use spark-submit for python applications
7072c6a [Andrew Or] Merge branch 'master' of github.com:apache/spark into python-examples
427a5f0 [Andrew Or] Update docs
d32072c [Andrew Or] Remove <master> from examples + update usages
Make deprecation warning less severe

Just a small change. I think it's good not to scare people who are using the old options.

Author: Patrick Wendell <pwendell@gmail.com>

Closes #810 from pwendell/warnings and squashes the following commits:

cb8a311 [Patrick Wendell] Make deprecation warning less severe
Fix spark-submit path in spark-shell & pyspark

Author: Neville Li <neville@spotify.com>

Closes #812 from nevillelyh/neville/v1.0 and squashes the following commits:

0dc33ed [Neville Li] Fix spark-submit path in pyspark
becec64 [Neville Li] Fix spark-submit path in spark-shell
SPARK-1873: Add README.md file when making distributions

Author: Patrick Wendell <pwendell@gmail.com>

Closes #818 from pwendell/reamde and squashes the following commits:

4020b11 [Patrick Wendell] SPARK-1873: Add README.md file when making distributions
[WIP][SPARK-1871][MLLIB] Improve MLlib guide for v1.0

Some improvements to MLlib guide:

1. [SPARK-1872] Update API links for unidoc.
2. [SPARK-1783] Added `page.displayTitle` to the global layout. If it is defined, use it instead of `page.title` for title display.
3. Add more Java/Python examples.

Author: Xiangrui Meng <meng@databricks.com>

Closes #816 from mengxr/mllib-doc and squashes the following commits:

ec2e407 [Xiangrui Meng] format scala example for ALS
cd9f40b [Xiangrui Meng] add a paragraph to summarize distributed matrix types
4617f04 [Xiangrui Meng] add python example to loadLibSVMFile and fix Java example
d6509c2 [Xiangrui Meng] [SPARK-1783] update mllib titles
561fdc0 [Xiangrui Meng] add a displayTitle option to global layout
195d06f [Xiangrui Meng] add Java example for summary stats and minor fix
9f1ff89 [Xiangrui Meng] update java api links in mllib-basics
7dad18e [Xiangrui Meng] update java api links in NB
3a0f4a6 [Xiangrui Meng] api/pyspark -> api/python
35bdeb9 [Xiangrui Meng] api/mllib -> api/scala
e4afaa8 [Xiangrui Meng] explicity state what might change