nx.tcl: - set multiplicty for mixins and filters by default from 1..n to 0..n to avoid error messages, when e.g. empty mixin lists are configured. Setting emtpy mixin-lists is strictly speaking not necessary, but this eases the code in cases the lists are sometimes empty.
- library/nx/nx.tcl: Following the code review, implemented a first scheme for handling traces in setCheckedInstVar. This gives us consistent behavior for defaults and traces (valuechangedcmd) across classes and objects. - tests/parameters.test: Adjusted the relevant tests - Pending: setCheckedInstVar currently uses ::nsf::is to validate the value (e.g., default value) to be set. However, it might get passed parameter options which do not fit the NSF_DISALLOWED_ARG_VALUECHECKED filter.