- nsf: added flag NSF_DESTROY_CALLED_SUCCESS in addition to NSF_DESTROY_CALLED to distinguish between attempted and successful destroy method invocations (important for cleanup)
- used Tcl_ObjCmdProc in prototypes - allow CMETHOD to be target of calling-object/calling-level - added NSF_CSC_CALL_IS_TRANSPARENT to handle proc aliases transparently - access self in NsfProcAliasMethod() from tcl->object