Handling for incremental mode in Characterization module

[anthonysena]

Scenario: When running the Characterization module, an error occurs which then stops the execution. When attempting to re-run Characterization, you encounter an error such as:

CharacterizationModule jobIds: tte_1,cac_1 executed but not completed.  Please run cleanIncremental() to remove incomplete results. 

Presumably, the module should look at the execution settings and if incremental mode is enabled, and run Characterization::cleanIncremental(workFolder)? Tagging @jreps for input.

[jreps]

Tagging @chrisknoll as he had opinions that this should not be automated when we wrote the latest Characterization. Perhaps this is not a problem for the module though?