Alternate approach to wiring up the counters
Fix typo
Move the keepAlive to the job class.

Remove the logger statements if flowProcess isn't defined. The sys.error in place means these statements will never be hit with a null.
Review comments
Move the UniqueID case class out of the Job class to avoid serializations of it grabbing a reference to its parent
Move the job conf variable name to be a constant in the Job object
Make the stats holders not need to be object globals
Resolve merge conflict
Null guard the property
Merge pull request #757 from twitter/feature/counter_classes

Alternate approach to wiring up the counters