Fix #137, issue references in comments

[aaaaalbert]

This set of commits addresses #137 by making uniform all issue references in comments in the repy_v2 code base. (I used the org--repo--issue format throughout, see also secure-systems-lab/code-style-guidelines#12.)

Please squash-merge this PR if you're happy with it. The separate commits are not terribly interesting, I just tried (and failed!) to go file-by-file.

BTW, here is how I found issue references in the code:

grep "#[0-9]" *
grep -i ticket *   # Trac called these things "tickets"
grep -i issue *    # This is the name we use now/on GitHub

[aaaaalbert]

Thanks a lot @lukpueh!