Fix Thor aliases

Fix some problems with the Thor aliases, namely:

- There was a conflicting alias.
- Multi-character aliases aren't supported by Thor.

On [multi-character aliases](https://github.com/erikhuda/thor/wiki/Method-Options#default-values):

> Note: Thor follows a convention of one-dash-one-letter options. Thus aliases like "-something" wont be parsed; use either "\--something" or "-s" instead.