Changed the fixture task and task results fields.

They no longer round trip the command class, but do round trip the
task type.

AFDP-117
Changed executor to cope with the task field changes.

AFDP-117
Created a factory to map from task types to task result commands.

AFDP-117
Changed task enroller to handle the lack of command class in the tasks.

AFDP-117
Changed handler to use the new task type to command mapping factory.

AFDP-117
Updated command to use the new task enroller API.

AFDP-117
Updated tests to handle the various task API changes.

AFDP-117
Merge pull request #43 from ualerts-org/AFDP-117

Afdp 117