[scala] Self-contained build for scala examples

This closes #199.
[FLINK-1218] Replace new Integer with Integer.valueOf in tests

This closes #183.
[FLINK-1239] [streaming] IterateExample fix and parallelism setting in StreamExecutionEnvironment made public

Conflicts:
	flink-addons/flink-streaming/flink-streaming-examples/src/main/java/org/apache/flink/streaming/examples/iteration/IterateExample.java
[FLINK-1233] Fix flaky AggregateITCase