SEEK

SEEK participants need to be able to create and edit workflows to explore the
expressiveness of the language. The current version of vergil does not support
editing the workflow before a java wrapper class has been created. Need to
modify vergil to allow scientists to easily create new stub classes that
represent analytical steps, and then use those in a workflow. The classes can
be implemented later in order to execute.

Requirements:
1) New actors added dynamically at run time, one per analytical step
2) Actors may be only stub interface classes
3) Actors accurately reflect the I/O interface needed for the analytical task
4) Newly created actors show up in library listing
5) Newly created actors can be used in workflows
6) Serialized workflows in MoML show new actors in workflow

Optional but useful:
7) Person who creates the actor can set its icon