tests: fix the flaky test test-logtoprocess.t The main change is that we're waiting for the [touched] file to appear for 5 seconds instead of 0.1 seconds. Also, instead of implementing wait-on-file from scratch, we use the existing one from testlib/ that works well.

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