Provide Tcl9 compatibility after TIP #673 TIP #673 removed "trace variable", which was deprecated since the release of Tcl 8.4. However, since Tcl does not warn about deprecations, so it was not detected until TIP #673 removed the command for Tcl9.
nsf.c: - change name of enumeratorConverterEntry to Nsf_EnumeratorConverterEntry, move it with NSF_ARG_* flags to tcl.h to make it available in derived modules using the converter - Added editor hints for a more uniform appearance