id ranges as command line argument

Make TimeWarrior commands accept id ranges which are then expanded into a list of ids and processed.

Syntax could be something like
```
timew @1 - @5
```

This would be useful for commands like `delete` (see also #124) but maybe also for `tag`, `join` and others.

Start by locating the command-line argument parsing entry point and how @id arguments are collected. Check the handling of delete, tag, and join, along with the discussion in #124; done means a range such as @1 - @5 expands into the individual ids and is processed by supported commands.

Written by the indexing model from the issue text.