Fixing RSpec deprecation warning 'mock is deprecated. Use double instead.'
Add ability to hide trace flags/globally enable tracing

Squashed:

    Add helper commands to delegates and some basic tests
    Don't show --trace text in error messages when it's disabled. Also updated naming as tracing isn't just hidden from the menu it's actually completely disabled
    Adding ability to hide --trace, -t from the menu and globally enable tracing via https://github.com/visionmedia/commander/issues/16#issuecomment-329635. Usage: Commander::Runner.instance.hide_trace_help

Don't show --trace text in error messages when it's disabled. Also updated naming as tracing isn't just hidden from the menu it's actually completely disabled

Squashed commit of the following:

commit 6120fe241a825a75f80afa5e861774ced61117f4
Author: James White <dev.jameswhite@gmail.com>
Date:   Mon Feb 10 17:03:55 2014 +0000

    Update README.md
Rename commands to `always_trace!`/`never_trace!`

Improve spec to test behavior of commands