Command Argument Handler

[hhenrichsen]

Command argument handling should be dead easy, but it's not yet. We'll need to introduce some new types in order to facilitate this.

• Tie ordered arguments to types and names.
• Validate these arguments based on the Validator System (#2).
• Send messages based on failures. Perhaps provide hooks for pass/fail, with default options?
• Short circuit or pile up all of them. Would be good to see all of the issues at once, but might get cluttered if something is missing.