Removes some dead val's, confuses the logging
I ran into a strange deadlock in the parhashset, so just go with a simpler approach that has been more robust
New debug log messages when using a Summer constructor
Merge pull request #536 from twitter/removeDeadVals

Few small updates
Merge pull request #537 from twitter/dag_processing

Initial add of the generic optimizer code
Merge branch 'develop' into future-memory