Moving all annotations to Java API
Moving all annotations from the core to the Java API package. Created SemanticProperties in the core to store properties inferred currently from Java annotations.
Moving all annotations to Java API.
Fix and comments.
Scala annotations fix.
Removing dependency to Combinable annotation.
Simplified and fixed estimate computation.
Fix estimate computation and add (enable) additional tests.
Merge branch 'estimates_rework' into japi
Part 6
Merge branch 'semantic-annotations' of https://github.com/jcamachor/stratosphere into annotations

Conflicts:
	stratosphere-compiler/src/main/java/eu/stratosphere/compiler/dag/OptimizerNode.java
	stratosphere-compiler/src/main/java/eu/stratosphere/compiler/dag/SingleInputNode.java
	stratosphere-compiler/src/main/java/eu/stratosphere/compiler/dag/TwoInputNode.java
	stratosphere-java/src/main/java/eu/stratosphere/api/java/record/operators/CoGroupOperator.java
	stratosphere-java/src/main/java/eu/stratosphere/api/java/record/operators/CrossOperator.java
	stratosphere-java/src/main/java/eu/stratosphere/api/java/record/operators/JoinOperator.java
	stratosphere-java/src/main/java/eu/stratosphere/api/java/record/operators/MapOperator.java
	stratosphere-java/src/main/java/eu/stratosphere/api/java/record/operators/ReduceOperator.java
Clean up moved annotations
Part 7