PINT special-cases parameters

[aarchiba]

Certain parameters, in particular DMDATA and START/FINISH are treated specially by PINT - that is, START/FINISH are explicitly checked to ensure that they are never fit for, and DMDATA is a boolParameter but its output (and no other boolParameter) is overridden to be 0/1 instead of the usual Y/N for TEMPO compatibility. These special cases should be set up as options on the Parameter objects when they are created, so that (for example) when the START parameter is created one can ensure that it is never fittable, without the rest of PINT needing to treat START specially.

These two changes are introduced in #1230, which is otherwise rather badly needed, so this issue is here to remind us to fix the temporary hack.

[abhisrkckl]

This issue was solved as a side effect of #1640.