prefix leg names with original proc name

[Ico Doornekamp]

That would make trace() output much more readable.

[Smooth Operator]

I don't have any great ideas on how to do this trivially without cheating with a global or something, but here's what I came up with:

We get more strict about using newAnnotation, and we have it pass the original cps procedure's identifier and maybe a bunch of other interesting data. Then we use debugAnnotation to also shadow makeContProc with a closure that first mutates the name argument. To that end, I rewrote cpsTryExcept in bf9f476 to also use debugAnnotation. I think that's the only outstanding case that both calls makeContProc and was lacking the debugAnnotation syntax.

[Smooth Operator]

This is also a #190 problem.