Make cayley go gettable about cayley

[barakmich]

It's worth considering. What sorts of invasive changes? Not necessarily opposed to them, just having some more context before I say "yeah, go ahead!" would be cool.

[kortschak]

I'm just relaxing into it at the moment, so you can have a look and feel free to reject.

[kortschak]

The changes are here. I'll send a PR and sign a CLA if you're happy with that.

There are other changes that I think would be worthwhile to get the code to be more Go-idiomatic and which should ease reading, but I'll wait on whether your not averse to this load first.

[barakmich]

Yeah, send the PR. I'll do a full review later tonight (when I get away from I/O) but my initial glance made me go "oh, neat!" so that's a good sign. When I get ready to accept the PR, at that point you can do the CLA (and add yourself to the CONTRIBUTORS file).