Allow nesting commands under minion names in master ACL config

[johnccfm]

The current code allows ACL's like:-

client_acl:
  # Allow thatch to execute anything.
  thatch:
    - .*

But it breaks horribly on ACL's like:-

client_acl:
  # Allow fred to use test and pkg, but only on "web*" minions.
  fred:
    - web*:
      - test.*
      - pkg.*

This patch fixes this - perhaps not in the safest or most elegant way, but it seems to work.

[gravyboat]

Did you close this on purpose?

Edit: nevermind i realized you have #209.