[SPARK-2395][SQL] Optimize common LIKE patterns.

Author: Michael Armbrust <michael@databricks.com>

Closes #1325 from marmbrus/slowLike and squashes the following commits:

023c3eb [Michael Armbrust] add comment.
8b421c2 [Michael Armbrust] Handle the case where the final % is actually escaped.
d34d37e [Michael Armbrust] add periods.
3bbf35f [Michael Armbrust] Roll back changes to SparkBuild
53894b1 [Michael Armbrust] Fix grammar.
4094462 [Michael Armbrust] Fix grammar.
6d3d0a0 [Michael Armbrust] Optimize common LIKE patterns.

(cherry picked from commit cc3e0a14daf756ff5c2d4e7916438e175046e5bb)
Signed-off-by: Michael Armbrust <michael@databricks.com>
[SPARK-2403] Catch all errors during serialization in DAGScheduler

https://issues.apache.org/jira/browse/SPARK-2403

Spark hangs for us whenever we forget to register a class with Kryo. This should be a simple fix for that. But let me know if you have a better suggestion.

I did not write a new test for this. It would be pretty complicated and I'm not sure it's worthwhile for such a simple change. Let me know if you disagree.

Author: Daniel Darabos <darabos.daniel@gmail.com>

Closes #1329 from darabos/spark-2403 and squashes the following commits:

3aceaad [Daniel Darabos] Print full stack trace for miscellaneous exceptions during serialization.
52c22ba [Daniel Darabos] Only catch NonFatal exceptions.
361e962 [Daniel Darabos] Catch all errors during serialization in DAGScheduler.

(cherry picked from commit c8a2313cdf825e0191680a423d17619b5504ff89)
Signed-off-by: Aaron Davidson <aaron@databricks.com>
[SPARK-2409] Make SQLConf thread safe.

Author: Reynold Xin <rxin@apache.org>

Closes #1334 from rxin/sqlConfThreadSafetuy and squashes the following commits:

c1e0a5a [Reynold Xin] Fixed the duplicate comment.
7614372 [Reynold Xin] [SPARK-2409] Make SQLConf thread safe.

(cherry picked from commit 32516f866a32d51bfaa04685ae77ba216b4202d9)
Signed-off-by: Reynold Xin <rxin@apache.org>
[SPARK-2362] Fix for newFilesOnly logic in file DStream

The newFilesOnly logic should be inverted: the logic should be that if the flag newFilesOnly==true then only start reading files older than current time. As the code is now if newFilesOnly==true then it will start to read files that are older than 0L (that is: every file in the directory).

Author: Gabriele Nizzoli <mail@nizzoli.net>

Closes #1077 from gabrielenizzoli/master and squashes the following commits:

4f1d261 [Gabriele Nizzoli] Fix for newFilesOnly logic in file DStream

(cherry picked from commit e6f7bfcfbf6aff7a9f8cd8e0a2166d0bf62b0912)
Signed-off-by: Tathagata Das <tathagata.das1565@gmail.com>