Add Mesos config to spark-env.sh
KillTask stub
Only do Accumulator updates when there's new stuff
Add executor URI
Fix executor URI
SPARK-1806: Upgrade Mesos dependency to 0.18.1

Enabled Mesos (0.18.1) dependency with shaded protobuf

Why is this needed?
Avoids any protobuf version collision between Mesos and any other
dependency in Spark e.g. Hadoop HDFS 2.2+ or 1.0.4.

Ticket: https://issues.apache.org/jira/browse/SPARK-1806

* Should close https://issues.apache.org/jira/browse/SPARK-1433

Author berngp

Author: Bernardo Gomez Palacio <bernardo.gomezpalacio@gmail.com>

Closes #741 from berngp/feature/SPARK-1806 and squashes the following commits:

5d70646 [Bernardo Gomez Palacio] SPARK-1806: Upgrade Mesos dependency to 0.18.1
Put mesos config behind a flag
Just check if SPARK_ON_MESOS is set
Merge pull request #11 from Shopify/mesos

Mesos