SPARK-1456 Remove view bounds on Ordered in favor of a context bound on Ordering.

This doesn't require creating new Ordering objects per row.  Additionally, [view bounds are going to be deprecated](https://issues.scala-lang.org/browse/SI-7629), so we should get rid of them while APIs are still flexible.

Author: Michael Armbrust <michael@databricks.com>

Closes #410 from marmbrus/viewBounds and squashes the following commits:

c574221 [Michael Armbrust] fix example.
812008e [Michael Armbrust] Update Java API.
1b9b85c [Michael Armbrust] Update scala doc.
35798a8 [Michael Armbrust] Remove view bounds on Ordered in favor of a context bound on Ordering.
SPARK-1482: Fix potential resource leaks in saveAsHadoopDataset and save...

...AsNewAPIHadoopDataset

`writer.close` should be put in the `finally` block to avoid potential resource leaks.

JIRA: https://issues.apache.org/jira/browse/SPARK-1482

Author: zsxwing <zsxwing@gmail.com>

Closes #400 from zsxwing/SPARK-1482 and squashes the following commits:

06b197a [zsxwing] SPARK-1482: Fix potential resource leaks in saveAsHadoopDataset and saveAsNewAPIHadoopDataset
README update

Author: Reynold Xin <rxin@apache.org>

Closes #443 from rxin/readme and squashes the following commits:

16853de [Reynold Xin] Updated SBT and Scala instructions.
3ac3ceb [Reynold Xin] README update
Use scala deprecation instead of java.

This gets rid of a warning when compiling core (since we were depending on a deprecated interface with a non-deprecated function).  I also tested with javac, and this does the right thing when compiling java code.

Author: Michael Armbrust <michael@databricks.com>

Closes #452 from marmbrus/scalaDeprecation and squashes the following commits:

f628b4d [Michael Armbrust] Use scala deprecation instead of java.
Add insertInto and saveAsTable to Python API.

Author: Michael Armbrust <michael@databricks.com>

Closes #447 from marmbrus/pythonInsert and squashes the following commits:

c7ab692 [Michael Armbrust] Keep docstrings < 72 chars.
ff62870 [Michael Armbrust] Add insertInto and saveAsTable to Python API.
[SPARK-1535] ALS: Avoid the garbage-creating ctor of DoubleMatrix

`new DoubleMatrix(double[])` creates a garbage `double[]` of the same length as its argument and immediately throws it away.  This pull request avoids that constructor in the ALS code.

Author: Tor Myklebust <tmyklebu@gmail.com>

Closes #442 from tmyklebu/foo2 and squashes the following commits:

2784fc5 [Tor Myklebust] Mention that this is probably fixed as of jblas 1.2.4; repunctuate.
a09904f [Tor Myklebust] Helper function for wrapping Array[Double]'s with DoubleMatrix's.
REPL cleanup.

Author: Michael Armbrust <michael@databricks.com>

Closes #451 from marmbrus/replCleanup and squashes the following commits:

088526a [Michael Armbrust] REPL cleanup.