Hash Tables Management

`GB_HASHTABLE`	Hash table datatype.
`GB.HashTable.Add`	Inserts an element in a hash table.
`GB.HashTable.Count`	Returns the number of elements in a hash table.
`GB.HashTable.Enum`	Enumerates a hash table.
`GB_HASHTABLE_ENUM_FUNC`	Hash table enumeration function.
`GB.HashTable.Free`	Deletes a hash table.
`GB.HashTable.Get`	Retrieves an element from a hash table.
`GB.HashTable.New`	Creates a new hash table.
`GB.HashTable.Remove`	Removes an element from a hash table.