PONYO_CONTAINER_MAP

This is a high-level interface that allows the underlying implementation to change over time as its optimized. The current implementation uses a binary search tree.
Examples:
StringMap = Ponyo_Container_Map (Ponyo_String);
val config = StringMap.empty
val config = StringMap.insert (config, ("PRODUCTION", 1))
val config = StringMap.insert (config, ("DEVELOPMENT", 2))
val develLevel = StringMap.get (config, "DEVELOPMENT")