tests/testlib/common.sh

rustdoc: nodemap doc refreshing

Not pretending to be comprehensive.

- correcting some inconsistencies
- adding a few missing doc-comments
- adding more cross references (in some cases it's right beside
  the current documentation item, but it will nevertheless also
  be useful, because `rustdoc` will warn us if inconsistencies
  arise).

mkcommit() {
   name="$1"
   shift
   echo "$name" > "$name"
   hg add "$name"
   hg ci -m "$name" "$@"
}