Add scalding.Execution to run scalding flows without a Job
Merge branch 'develop' into oscar-executor
Add ExecutionContext
Fix a comment
Remove config from Mode
Add a Try around the Flow, since cascading throws on a lot of planning problems
Add some better comments on how to use the Execution object
Add some tests
Merge pull request #915 from twitter/oscar-executor

Add an Executor to run flows without a Job