Add debug guardians to suppress string generation which caused a significant performance loss.
Add startup timeout config parameter. Increase akka ask timeouts for integration tests. Increase akka logger startup timeout.
Use container based builds in travis. Enable caching for travis. Set travis fork count to 2.
Change integration tests to reuse cluster in order to save startup and shutdown time.
Add option to use single actor system for local execution. Use local connection manager if a single task manager is used for local execution. Remove synchronized blcok in getReceiverList of ChannelManager which effectively serialized the connection lookup calls of a single task manager.

Fix Java6 problem that File has no method toPath
Execute lookupConnectionInformation and UpdateTaskExecutionState concurrently within futures