Additional operations for the MONO_HASH_TABLE interface

[Skyb0rg007]

Description

The hash table in the SML/NJ library is missing some operations that would be useful.

signature MONO_HASH_TABLE = sig
  (* ... *)
  (* Same as those in ORD_MAP *)
  val insertWith : ('a * 'a -> 'a) -> 'a hash_table -> Key.hash_key * 'a -> unit
  val findAndRemove : 'a hash_table -> Key.hash_key -> 'a option
end

[JohnReppy]

These have been implemented for 110.99.5. Also added the functions to the HashTable structure.