[SPARK-2805] Upgrade Akka to 2.3.4

This is a second rev of the Akka upgrade (earlier merged, but reverted). I made a slight modification which is that I also upgrade Hive to deal with a compatibility issue related to the protocol buffers library.

Author: Anand Avati <avati@redhat.com>
Author: Patrick Wendell <pwendell@gmail.com>

Closes #2752 from pwendell/akka-upgrade and squashes the following commits:

4c7ca3f [Patrick Wendell] Upgrading to new hive->protobuf version
57a2315 [Anand Avati] SPARK-1812: streaming - remove tests which depend on akka.actor.IO
2a551d3 [Anand Avati] SPARK-1812: core - upgrade to akka 2.3.4
[SPARK-3889] Attempt to avoid SIGBUS by not mmapping files in ConnectionManager

In general, individual shuffle blocks are frequently small, so mmapping them often creates a lot of waste. It may not be bad to mmap the larger ones, but it is pretty inconvenient to get configuration into ManagedBuffer, and besides it is unlikely to help all that much.

Author: Aaron Davidson <aaron@databricks.com>

Closes #2742 from aarondav/mmap and squashes the following commits:

a152065 [Aaron Davidson] Add other pathway back
52b6cd2 [Aaron Davidson] [SPARK-3889] Attempt to avoid SIGBUS by not mmapping files in ConnectionManager
[SPARK-3886] [PySpark] use AutoBatchedSerializer by default

Use AutoBatchedSerializer by default, which will choose the proper batch size based on size of serialized objects, let the size of serialized batch fall in into  [64k - 640k].

In JVM, the serializer will also track the objects in batch to figure out duplicated objects, larger batch may cause OOM in JVM.

Author: Davies Liu <davies.liu@gmail.com>

Closes #2740 from davies/batchsize and squashes the following commits:

52cdb88 [Davies Liu] update docs
185f2b9 [Davies Liu] use AutoBatchedSerializer by default
HOTFIX: Fix build issue with Akka 2.3.4 upgrade.

We had to upgrade our Hive 0.12 version as well to deal with a protobuf
conflict (both hive and akka have been using a shaded protobuf version).
This is testing a correctly patched version of Hive 0.12.

Author: Patrick Wendell <pwendell@gmail.com>

Closes #2756 from pwendell/hotfix and squashes the following commits:

cc979d0 [Patrick Wendell] HOTFIX: Fix build issue with Akka 2.3.4 upgrade.
[SPARK-2924] Required by scala 2.11, only one fun/ctor amongst overriden alternatives, can have default argument(s).

...riden alternatives, can have default argument.

Author: Prashant Sharma <prashant.s@imaginea.com>

Closes #2750 from ScrapCodes/SPARK-2924/default-args-removed and squashes the following commits:

d9785c3 [Prashant Sharma] [SPARK-2924] Required by scala 2.11, only one function/ctor amongst overriden alternatives, can have default argument.
Passing ContantObjectInspector(when necessary) for UDF initializing