Deprecate: Deprecate all functions under `fitbase`

[cadenmyers13]

Problem

We still use camel case function naming and we want to move to snake case. The following files need to be review for deprecation:

• __init__.py
• calculator.py
• configurable.py
• constraint.py
• fitcontribution.py
• fithook.py
• fitrecipe.py
• fitresults.py
• parameter.py
• parameterset.py
• profile.py
• profilegenerator.py
• profileparser.py
• recipeorganizer.py
• restraint.py
• simplerecipe.py
• validatable.py

Proposed solution

Follow instructions here to deprecate: diffpy/diffpy.utils#366 (comment)