nsf.c: - new cmd for debugging: nsf::__db_show_obj - added MethodDupInternalRep() and FlagDupInternalRep() since they appear to be required in Tcl 8.6b2.
nsf.c: - reform of method lookup. new code uses NsfInstanceMethodObjType and NsfObjectMethodObjType to reuse earlier lookup results. Improved speed for for methods with primitive bodies (over version before argument parse reform: 10%-43%. - additional compile-time option: METHOD_OBJECT_TRACE