Migrating to version 3

Version 3 API becomes simpler.

Here is the changes:

Version 2Version 3Description
State.[self]N/Aself property has been removed. It is not necessary to use [self] property anymore in order to access state methods. Check out update nested states section for details about accessing nested states and state methods.
StateMethods.keys()StateMethods.keykeys now is a property, not a method.
StateMethods.map(...)N/Amap method has been removed as it was confusing and conflicting with Array.map. Asynchronous state and Exporting state sections have been updated to use the alternative to map syntax.