This release mainly improves method merging internals.

Chainable is an alternative to alias_method_chain, that uses inheritance, rather than aliasing. It does the following when "chaining" a method:

* copy the original method to a new model
* include the model
* overwrite the method

Thus you can use super and keep your method list clean, too! It even supports a (rather dangerous) auto chaining mode, so you do not have to explicitly chain a method, but chain a method whenever it would be overwritten instead.