Design creation ignores initialization order

The initialization order turns out to be irrelevant when initializing
parameters during design creation. This should be pretty obvious, since
dependent parameters are initialized recursively anyway.

Taking initialization order into account might offer a small
performance saving, but it is unlikely to be significant. However, it's
likely that it would interfere when dealing with choices in the future.
Removed getContext from SParam
Renamed Param to NParam
Expanded mapping equality test