Doc: minor fixes

- check for class/static methods assumed nonzero args.
- subclass references and set-flag items are now sorted.
- use 'order' for Py operator mix-ins,
  so operator settings don't show in random order.

release/scripts/modules/rna_info.py

@@ -268,7 +268,8 @@ class InfoPropertyRNA:
             self.default_str = "\"%s\"" % self.default
         elif self.type == "enum":
             if self.is_enum_flag:
-                self.default_str = "%r" % self.default  # repr or set()
+                # self.default_str = "%r" % self.default  # repr or set()
+                self.default_str = "{%s}" % repr(list(sorted(self.default)))[1:-1]
             else:
                 self.default_str = "'%s'" % self.default
         elif self.array_length: