[5pt] Integrate steps 1 to 6 into ras2fim

We are getting near the point of integrating Step 1 to 6 components into ras2fim.py.  A few things need to happen first:
- PR 233 (step 6 / create rating curves and bug fix for Step 2 conflate) is merged.
- Issue 236: fix  Step 5 so that worker_fim_rasters.py is integrated back into create_fim_rasters.py.  

Note: Other fixes are coming in the near future but won't block integration at this point.