Joining the packet sources

[xoft]

I don't think Lua minds if you call its function with more parameters than it actually declares. So for added fields, we can simply add them and plugins will continue working. For fields that are removed, we can simply pass in a default value. And worst case scenario, changed fields, can be expressed as a combination of add + remove.

We'll see how it works, if it's not good enough, we can pack it in structures later on.