1.1

• Melded the API of foreign-var 0.1 with the API of StateVar 1.0.1.1
• Introduced HasUpdate, which permits a wider array of uses of these combinators, including usecases that must update atomically.
• Switched to multi-parameter typeclasses. This permits Ptr a to be directly employed as an instance of HasGetter, HasUpdate, and HasSetter.