Unified package definition format in Spark SQL

According to discussions in comments of PR #208, this PR unifies package definition format in Spark SQL.

Some broken links in ScalaDoc and typos detected along the way are also fixed.

Author: Cheng Lian <lian.cs.zju@gmail.com>

Closes #225 from liancheng/packageDefinition and squashes the following commits:

75c47b3 [Cheng Lian] Fixed file line length
4f87968 [Cheng Lian] Unified package definition format in Spark SQL
[SQL] Un-ignore a test that is now passing.

Add golden answer for aforementioned test.

Also, fix golden test generation from sbt/sbt by setting the classpath correctly.

Author: Michael Armbrust <michael@databricks.com>

Closes #244 from marmbrus/partTest and squashes the following commits:

37a33c9 [Michael Armbrust] Un-ignore a test that is now passing, add golden answer for aforementioned test.  Fix golden test generation from sbt/sbt.
[SQL] Add a custom serializer for maps since they do not have a no-arg constructor.

Author: Michael Armbrust <michael@databricks.com>

Closes #243 from marmbrus/mapSer and squashes the following commits:

54045f7 [Michael Armbrust] Add a custom serializer for maps since they do not have a no-arg constructor.
SPARK-1324: SparkUI Should Not Bind to SPARK_PUBLIC_DNS

/cc @aarondav and @andrewor14

Author: Patrick Wendell <pwendell@gmail.com>

Closes #231 from pwendell/ui-binding and squashes the following commits:

e8025f8 [Patrick Wendell] SPARK-1324: SparkUI Should Not Bind to SPARK_PUBLIC_DNS
Spark 1095 : Adding explicit return types to all public methods

Excluded those that are self-evident and the cases that are discussed in the mailing list.

Author: NirmalReddy <nirmal_reddy2000@yahoo.com>
Author: NirmalReddy <nirmal.reddy@imaginea.com>

Closes #168 from NirmalReddy/Spark-1095 and squashes the following commits:

ac54b29 [NirmalReddy] import misplaced
8c5ff3e [NirmalReddy] Changed syntax of unit returning methods
02d0778 [NirmalReddy] fixed explicit types in all the other packages
1c17773 [NirmalReddy] fixed explicit types in core package
SPARK-1325. The maven build error for Spark Tools

This is just a slight variation on https://github.com/apache/spark/pull/234 and alternative suggestion for SPARK-1325. `scala-actors` is not necessary. `SparkBuild.scala` should be updated to reflect the direct dependency on `scala-reflect` and `scala-compiler`. And the `repl` build, which has the same dependencies, should also be consistent between Maven / SBT.

Author: Sean Owen <sowen@cloudera.com>
Author: witgo <witgo@qq.com>

Closes #240 from srowen/SPARK-1325 and squashes the following commits:

25bd7db [Sean Owen] Add necessary dependencies scala-reflect and scala-compiler to tools. Update repl dependencies, which are similar, to be consistent between Maven / SBT in this regard too.
[SPARK-1327] GLM needs to check addIntercept for intercept and weights

GLM needs to check addIntercept for intercept and weights. The current implementation always uses the first weight as intercept. Added a test for training without adding intercept.

JIRA: https://spark-project.atlassian.net/browse/SPARK-1327

Author: Xiangrui Meng <meng@databricks.com>

Closes #236 from mengxr/glm and squashes the following commits:

bcac1ac [Xiangrui Meng] add two tests to ensure {Lasso, Ridge}.setIntercept will throw an exceptions
a104072 [Xiangrui Meng] remove protected to be compatible with 0.9
0e57aa4 [Xiangrui Meng] update Lasso and RidgeRegression to parse the weights correctly from GLM mark createModel protected mark predictPoint protected
d7f629f [Xiangrui Meng] fix a bug in GLM when intercept is not used