Catching UimaException's

[CollinM]

While the powers of type safety keep the exploration side of the system robust, the execution side of the system is still dependent on user-supplied components that we have no control over. So, let's add a try-catch in the relevant piece of executor code to prevent a full system crash whenever a component misbehaves. However, this error should not be caught silently, the result should be logged somewhere for review. The branch/trace that was being executed is now a dead-end and that information needs to be passed back to the explorer/controller so that the branch can be avoided and prevent any downstream errors.

[CollinM]

I'm going to list relevant exceptions as I (accidentally) create them while developing pipelines:

• org.apache.uima.analysis_engine.AnalysisEngineProcessException