Put links to the source definitions from the api docs, just like in twisted's docs

[cwillu]

I've found the direct links to the source code in twisted to be an invaluable aid to understanding, well, just about everything. What the doc is talking about, what implications of the docs are actually true, to say nothing of a ready-made example of what I need to do if I need something somewhat different than what's available.

I suspect, for instance, that I only managed to figure out how to build my conch-based call-in support monster because of the quick linking. (If said monster is unpalatable, forget I said anything :p)

While the source is obviously sitting right near-by my code in my properly configured virtualenv, it's still a bit of a nontrivial half-second-to-three-second speed bump to find my place, and leaves open the possibility of looking at a similarly named but very different thing, with the associated confusion caused thereby. I don't know of any troublesome examples of that in tubes yet, but I hope you agree it's only a matter of time.