Changes related to making things work with DEAP 1.0:
 - Moved calculations module to the top of the tree
 - Added a run_refinement method to the calculations module to allow for parallel refinement runs
 - Moved multiprocessing pool setup & handling to generic/pool.py module (instead of core.py and setting.py)
 - Disable caching by default, speed increase is usually not worth the trouble of clearing a huge file cache every time it starts up
 - Updated DEAP refinement methods to match with DEAP 1.0 API
 - Updated DEAP refinement methods to allow stopping them from the UI
 - Created a custom Cancellable and HasAsyncCalls base class (generic.async module) (cfr. point above)