SPARK-1063 Add .sortBy(f) method on RDD

This never got merged from the apache/incubator-spark repo (which is now deleted) but there had been several rounds of code review on this PR there.

I think this is ready for merging.

Author: Andrew Ash <andrew@andrewash.com>

This patch had conflicts when merged, resolved by
Committer: Reynold Xin <rxin@apache.org>

Closes #369 from ash211/sortby and squashes the following commits:

d09147a [Andrew Ash] Fix Ordering import
43d0a53 [Andrew Ash] Fix missing .collect()
29a54ed [Andrew Ash] Re-enable test by converting to a closure
5a95348 [Andrew Ash] Add license for RDDSuiteUtils
64ed6e3 [Andrew Ash] Remove leaked diff
d4de69a [Andrew Ash] Remove scar tissue
63638b5 [Andrew Ash] Add Python version of .sortBy()
45e0fde [Andrew Ash] Add Java version of .sortBy()
adf84c5 [Andrew Ash] Re-indent to keep line lengths under 100 chars
9d9b9d8 [Andrew Ash] Use parentheses on .collect() calls
0457b69 [Andrew Ash] Ignore failing test
99f0baf [Andrew Ash] Merge branch 'master' into sortby
222ae97 [Andrew Ash] Try moving Ordering objects out to a different class
3fd0dd3 [Andrew Ash] Add (failing) test for sortByKey with explicit Ordering
b8b5bbc [Andrew Ash] Align remove extra spaces that were used to align ='s in test code
8c53298 [Andrew Ash] Actually use ascending and numPartitions parameters
381eef2 [Andrew Ash] Correct silly typo
7db3e84 [Andrew Ash] Support ascending and numPartitions params in sortBy()
0f685fd [Andrew Ash] Merge remote-tracking branch 'origin/master' into sortby
ca4490d [Andrew Ash] Add .sortBy(f) method on RDD
SPARK-2146.  Fix takeOrdered doc

Removes Python syntax in Scaladoc, corrects result in Scaladoc, and removes irrelevant cache() call in Python doc.

Author: Sandy Ryza <sandy@cloudera.com>

Closes #1086 from sryza/sandy-spark-2146 and squashes the following commits:

185ff18 [Sandy Ryza] Use Seq instead of Array
c996120 [Sandy Ryza] SPARK-2146.  Fix takeOrdered doc
SPARK-2038: rename "conf" parameters in the saveAsHadoop functions

to distinguish with SparkConf object

https://issues.apache.org/jira/browse/SPARK-2038

Author: CodingCat <zhunansjtu@gmail.com>

Closes #1087 from CodingCat/SPARK-2038 and squashes the following commits:

763975f [CodingCat] style fix
d91288d [CodingCat] rename "conf" parameters in the saveAsHadoop functions
[SPARK-2147 / 2161] Show removed executors on the UI

This PR includes two changes
- **[SPARK-2147]** When an application finishes cleanly (i.e. `sc.stop()` is called), all of its executors used to disappear from the Master UI. This no longer happens.
- **[SPARK-2161]** This adds a "Removed Executors" table to Master UI, so the user can find out why their executors died from the logs, for instance. The equivalent table already existed in the Worker UI, but was hidden because of a bug (the comment `//scalastyle:off` disconnected the `Seq[Node]` that represents the HTML for table).

This should go into 1.0.1 if possible.

Author: Andrew Or <andrewor14@gmail.com>

Closes #1102 from andrewor14/remember-removed-executors and squashes the following commits:

2e2298f [Andrew Or] Add hash code method to ExecutorInfo (minor)
abd72e0 [Andrew Or] Merge branch 'master' of github.com:apache/spark into remember-removed-executors
792f992 [Andrew Or] Add missing equals method in ExecutorInfo
3390b49 [Andrew Or] Add executor state column to WorkerPage
161f8a2 [Andrew Or] Display finished executors table (fix bug)
fbb65b8 [Andrew Or] Removed unused method
c89bb6e [Andrew Or] Add table for removed executors in MasterWebUI
fe47402 [Andrew Or] Show exited executors on the Master UI