changed number of allocators per group back to 4
Implemented the second half of the EventLoopGroup refactoring. Also several smaller deadlock issues have been removed.
Removed a resource leak in the WorkloadManager. Also the SanityClient has been enhanced with new tests significantly.
Merge pull request #6 from Teots/master

EventLoopGroup Refactoring
Merge branch 'master' of github.com:citlab/AURA

Conflicts:
	aura-core/src/main/java/de/tuberlin/aura/core/memory/MemoryManager.java
	aura-examples/src/main/java/de/tuberlin/aura/demo/client/Client.java