[Test] Better exception message from SparkSubmitSuite

Before:
```
Exception in thread "main" java.lang.Exception: Could not load user defined classes inside of executors
	at org.apache.spark.deploy.JarCreationTest$.main(SparkSubmitSuite.scala:471)
	at org.apache.spark.deploy.JarCreationTest.main(SparkSubmitSuite.scala)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
```
After:
```
Exception in thread "main" java.lang.Exception: Could not load user class from jar:
java.lang.UnsupportedClassVersionError: SparkSubmitClassA : Unsupported major.minor version 51.0
	java.lang.ClassLoader.defineClass1(Native Method)
	java.lang.ClassLoader.defineClass(ClassLoader.java:643)
	...
	at org.apache.spark.deploy.JarCreationTest$.main(SparkSubmitSuite.scala:472)
	at org.apache.spark.deploy.JarCreationTest.main(SparkSubmitSuite.scala)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
```

Author: Andrew Or <andrew@databricks.com>

Closes #3212 from andrewor14/submit-suite-message and squashes the following commits:

7779248 [Andrew Or] Format exception
8fe6719 [Andrew Or] Better exception message from failed test

(cherry picked from commit 6e3c5a296c90a551be5e6c7292a66f2e65338240)
Signed-off-by: Andrew Or <andrew@databricks.com>
[SPARK-4281][Build] Package Yarn shuffle service into its own jar

This is another addendum to #3082, which added the Yarn shuffle service to run inside the NM. This PR makes the feature much more usable by packaging enough dependencies into the jar to run the service inside an NM. After these changes, the user can run `./make-distribution.sh` and find a `spark-network-yarn*.jar` in their `lib` directory. The equivalent change is done in SBT by making the `network-yarn` module an assembly project.

Author: Andrew Or <andrew@databricks.com>

Closes #3147 from andrewor14/yarn-shuffle-build and squashes the following commits:

bda58d0 [Andrew Or] Fix line too long
81e9705 [Andrew Or] Merge branch 'master' of github.com:apache/spark into yarn-shuffle-build
fb7f398 [Andrew Or] Rename jar to spark-{VERSION}-yarn-shuffle.jar
65db822 [Andrew Or] Actually mark slf4j as provided
abcefd1 [Andrew Or] Do the same for SBT
c653028 [Andrew Or] Package network-yarn and its dependencies

(cherry picked from commit aa43a8da012cf0dac7c7fcccde5f028a942599f0)
Signed-off-by: Andrew Or <andrew@databricks.com>
Internal cleanup for aggregateMessages

1. Add EdgeActiveness enum to represent activeness criteria more cleanly than using booleans.
2. Comments and whitespace.

Author: Ankur Dave <ankurdave@gmail.com>

Closes #3231 from ankurdave/aggregateMessages-followup and squashes the following commits:

3d485c3 [Ankur Dave] Internal cleanup for aggregateMessages

(cherry picked from commit 0402be90f7af82c8404cafbca79f5f9fb8e2bbed)
Signed-off-by: Reynold Xin <rxin@databricks.com>
[Release] Correct make-distribution.sh log path
[SPARK-3666] Extract interfaces for EdgeRDD and VertexRDD

This discourages users from calling the VertexRDD and EdgeRDD constructor and makes it easier for future changes to ensure backward compatibility.

Author: Ankur Dave <ankurdave@gmail.com>

Closes #2530 from ankurdave/SPARK-3666 and squashes the following commits:

d681f45 [Ankur Dave] Define getPartitions and compute in abstract class for MIMA
1472390 [Ankur Dave] Merge remote-tracking branch 'apache-spark/master' into SPARK-3666
24201d4 [Ankur Dave] Merge remote-tracking branch 'apache-spark/master' into SPARK-3666
cbe15f2 [Ankur Dave] Remove specialized annotation from VertexRDD and EdgeRDD
931b587 [Ankur Dave] Use abstract class instead of trait for binary compatibility
9ba4ec4 [Ankur Dave] Mark (Vertex|Edge)RDDImpl constructors package-private
620e603 [Ankur Dave] Extract VertexRDD interface and move implementation to VertexRDDImpl
55b6398 [Ankur Dave] Extract EdgeRDD interface and move implementation to EdgeRDDImpl

(cherry picked from commit a5ef58113667ff73562ce6db381cff96a0b354b0)
Signed-off-by: Reynold Xin <rxin@databricks.com>
[SPARK-4369] [MLLib] fix TreeModel.predict() with RDD

Fix  TreeModel.predict() with RDD, added tests for it.

(Also checked that other models don't have this issue)

Author: Davies Liu <davies@databricks.com>

Closes #3230 from davies/predict and squashes the following commits:

81172aa [Davies Liu] fix predict

(cherry picked from commit bd86118c4e980f94916f892c76fb808fd4c8bd85)
Signed-off-by: Xiangrui Meng <meng@databricks.com>