Updated the POM files and scoped some dependencies more carefully.
Also, reef-examples now also creates a JAR that contains all its dependencies. It is called "reef-examples-0.1-SNAPSHOT-shaded.jar".

You can e.g. run the HelloREEF example on the local runtime via:

`java -cp reef-examples-0.1-SNAPSHOT-shaded.jar reef-examples-0.1-SNAPSHOT-shaded.jar`
Removed the creation of the YARN-with-dependencies JAR
Merge pull request #662 from Microsoft-CISL/weimer_pom_cleanup

POM cleanups