[cadenmyers13]

Implements the two helpers on Component that every component (peak profile, instrument, texture) uses for its refinable values:

• create_parameters_from(refinable_obj, names) creates the component's srfit Parameters from a pyobjcryst model. Each Parameter starts at ObjCryst's default value, with ObjCryst's limits as its bounds. names maps our Parameter names to ObjCryst's ({"eta0": "Eta0"}), so the names users see don't depend on ObjCryst's. Some of those can't be Python names (2ThetaDispl), and some will change when workarounds are replaced.
• push_parameters(refinable_obj) writes the Parameter values into a pyobjcryst model before each calculation.

Why the limits matter: ObjCryst silently clamps a value set outside its limits. If a fit steps to W = 2 while the limit is 1, srfit reports W = 2 but the pattern is calculated with W = 1, and the fit stops responding to W. To prevent this:

• The limits become the Parameters' bounds, so least_squares(..., bounds=recipe.get_bounds_array()) stays inside them.
• push_parameters raises a ValueError if a value gets past a limit anyway, naming the limit and the value ObjCryst would have used. All values are checked before any is written, so an error leaves the model unchanged.

    tests/test_component.py ..............                       [100%]
    14 passed

[cadenmyers13]

@sbillinge ready for merge. I closed the other PR because it was stalling #4