Coding style improvements to ticket.c

[clumens]

I've resisted doing these kinds of changes but there's several things about existing coding style (primarily, the lack of braces in a lot of places) that annoy me. And then once I started doing that, I found other things to do. This PR is mostly style stuff, though I also took the opportunity to simplify list_ticket.

I'm especially interested in a double check that handling the length of the string returned from list_ticket is correct.

Also - this builds on top of #152. The first four patches here are from that PR. Once that gets merged, I can rebase this one and they'll go away.