add SampleSet model in repository app
in SampleSet, set name should be unique within a project
update process_manager models..the only ugly tie-in to the repository app is the SampleSet import
 - major change here is the ProcessOutput model, this will store a file for the entire output of a ProcessRequest from a Worker
update reflow settings with process_manager app and add process_manager urls
add first process_manager views, templates, and url routes
register process_manager models with the admin