[SPARK-4802] [streaming] Remove receiverInfo once receiver is de-registered

  Once the streaming receiver is de-registered at executor, the `ReceiverTrackerActor` needs to
remove the corresponding reveiverInfo from the `receiverInfo` map at `ReceiverTracker`.

Author: Ilayaperumal Gopinathan <igopinathan@pivotal.io>

Closes #3647 from ilayaperumalg/receiverInfo-RTracker and squashes the following commits:

6eb97d5 [Ilayaperumal Gopinathan] Polishing based on the review
3640c86 [Ilayaperumal Gopinathan] Remove receiverInfo once receiver is de-registered

(cherry picked from commit 10d69e9cbfdabe95d0e513176d5347d7b59da0ee)
Signed-off-by: Tathagata Das <tathagata.das1565@gmail.com>
[SPARK-4671][Streaming]Do not replicate streaming block when WAL is enabled

Currently streaming block will be replicated when specific storage level is set, since WAL is already fault tolerant, so replication is needless and will hurt the throughput of streaming application.

Hi tdas , as per discussed about this issue, I fixed with this implementation, I'm not is this the way you want, would you mind taking a look at it? Thanks a lot.

Author: jerryshao <saisai.shao@intel.com>

Closes #3534 from jerryshao/SPARK-4671 and squashes the following commits:

500b456 [jerryshao] Do not replicate streaming block when WAL is enabled

(cherry picked from commit 3f5f4cc4e7b3bc458e0579d247a0652dca365853)
Signed-off-by: Tathagata Das <tathagata.das1565@gmail.com>
[SPARK-4606] Send EOF to child JVM when there's no more data to read.

Author: Marcelo Vanzin <vanzin@cloudera.com>

Closes #3460 from vanzin/SPARK-4606 and squashes the following commits:

031207d [Marcelo Vanzin] [SPARK-4606] Send EOF to child JVM when there's no more data to read.

(cherry picked from commit 7e2deb71c4239564631b19c748e95c3d1aa1c77d)
Signed-off-by: Josh Rosen <joshrosen@databricks.com>