Make parsing more robust

[jotaen]

For run --list it needs to parse the run.sh file to find all task names and titles.

The parsing is currently rather simplistic. For this run.sh task file…

run_foo() {
  run_bar() {
    echo 123
  }
  run_bar
}

foo='
run_baz() {
}
'

… it would report the tasks foo, bar, baz.

But actually there is only foo.