Caramel Corn

• #59 propagate uncertainty for dynamic calculations
• #60 refactor redundancy from static and dynamic calcs
• #61 create extensible calculator class to implement calculate() method
• #62 all layers use Meta for options
• #63 split calculations into separate parameters, treat them separately
  in DAG
• #78 model class parameter
• #79 merge PR
• #83 clean up index_registry()