Consider Supporting boxing primitives

[ecton]

This has some syntactic problems we need to solve. For example, if you put a boxed integer in a map, and then overwrite the value in the map, how does the developer distinguish between updating the boxed value and overwriting the map's entry with a new value.

Currently, I'm hoping that this won't be a majorly requested feature, as I don't really want to add a special operator for this.