[FLINK-1237] Add support for custom partitioners
  - Functions: GroupReduce, Reduce, Aggregate on UnsortedGrouping, SortedGrouping,
               Join (Java API & Scala API)
  - Manual partition on DataSet (Java API & Scala API)
  - Distinct operations provide semantic properties for preservation of distinctified fields
  - Tests for pushown (or not pushdown) of custom partitionings and forced rebalancing
  - Tests for GlobalProperties matching of partitionings
  - Caching of generated requested data properties for unary operators

This closes #207
[bin] Remove MaxPermSize parameter for JVM 1.8

This closes #200.
[FLINK-1209] [compiler] Improve error messages when forgetting to close an iteration
[FLINK-1250] [config] [docs] Correct and document config keys for heartbeat intervals and timeouts

This closes #212
[FLINK-1247] [docs] Fix broken links in documentation

This closes #213.
Minor code clean up to get rid of IntelliJ IDEA warnings

This closes #214.
Add byte array serialization to InstantiationUtil
Added getExecutionEnvironment to the DataSet of the Scala API.
[FLINK-1254] [compiler] Fix compiler bug for pipeline breaker placement

This closes #216
[FLINK-1253] [tests] Make sure tests do not die with garbage collection overhead exceeded

This closes #217
[FLINK-933] Add primitive input format to read a sequence of primitives

This closes #47
[FLINK-993] Primitive input format fails for invalid input. Adapted documentation.
[streaming] Source parallelism API update

The new preferred way is calling setParallelism() after adding the SourceFounction. This solution works any other operator.
[streaming] Fixed async buffer sending at end of AbstractInvokable
[FLINK-1142] Log information about I/O manager temp dirs

This closes #219.
Minor code clean up

This closes #221.
[FLINK-1252] Add support for serializing Date and Enums in the Java API
[FLINK-1251] Enums are now handled properly by the collection input format
[FLINK-1252] address pull request comments

This closes #215
Added binary input and output format which uses the objects' TypeSerializer to serialize them.

Added InputTypeConfigurable to TypeSerializerOutputFormat to support a more seamless integration.

This closes #218.