Cleanup and simplification in the taskmanager and the local instances and mini cluster.
Fixed log levels, code cleanups and restore the thread interruption states for JobManager and TaskManager
Fixed heartbeat thread and startup/shutdown races in TaskManager
Fix concurrency bugs in cluster manager and cluster manager tests.
Simplifications of instance loading at startup.
Clean up comments and fix doc errors
Adjust iteration low level tests for reduced memory footprint
Improve error logging on RPC server.
Adjust tests LocalDistributedExecutor for low memory settings on build servers.
Post-merge fixes.
connected components test case with 2 joins with the solution set
Migrated tests to TestBase2 (for stabilty)
Added Int, Short, Float, Double, and Long Serializer Tests
(Re)add TransitiveClosureNaive, fix join, add ITCase

Scala Join took left key selector for both sides of join. Re-enable
union. TransitiveClosureNaive uses union, this is tested in the ITCase.

Properly disable GlobalSchemaGenerator, the information it created has
not been used, only local field positions have been used.
Add tupleType() method to CsvReader that allows to read directly into subclasses of Tuple
Fix CSV reader tests and added comments to CSV reader.
Display Exceptions in the JobManager webinterface
Removed faulty constructor
Remove obsolete Broadcast Variable Join example.
Simplified translation of new Java API
added support for setting the DOP of individual operators