Introduction Modifications, add-ons, plugins, hooks - whatever your preferred name for them is - 3rd party code modifications are an important part of any successful web application. It wasn't that long ago that the way you did this was manually opening up files and copying and pasting bits of code in, or the really cool web applications had points scattered throughout the code for modifications to be injected into, or even scripts which opened up the files and made the changes for you (I'm no