Java pi and record api namespace unified.
WorksetIteration changed to DeltaIteration.
fix hdfs for hadoop 2.2
fix yarn copyright
adopted hadoop configuration for hadoop 2.2.0

Add accumulators to web interface

Conflicts:
	stratosphere-core/src/main/java/eu/stratosphere/configuration/ConfigConstants.java
	README.md
fixed stratosphere-client's classpath
added debugging msgs to yarn, changed ajax requests to relative paths