Rails and Merb Merge: Plugin API (Part 3 of 6)

I started off this series on the Rails/Merb merge (aka Rails 3) talking about modularity, and then performance. Next up, plugins! When we announced the Rails/Merb merge, we promised to bring a more stable plugin API to Rails 3. Merb had strong opinions about an explicitly exposed plugin API, so we hoped to end the complications of alias_method_chain in favor of exposed APIs which plugin authors co