add to_octets

src/binary_formats.ml

@@ -20,7 +20,12 @@
    - test them
    - some purpose (`TALER_SIGNATURE_XXX`) are missing
      exchange and gana master branch are not in sync
-     and we should use a specific git tag instead *)
+     and we should use a specific git tag instead
+
+   - clean up functor mess
+     don't have not hash thing be HashCode like
+   - have a make function for wrapped HashCode structs
+     make it take the relevant type *)
 
 module Taler_signatures = Include.Taler_signatures