Initial revision

Summary:
To run several masters on one server, we provide different
configuration directories, and map staging directories to
them.

The salt-get-config-dir command gives the config dir to
use in stdout, or return 1 as exit code if that can't be
determined.

The salt-wrapper command generates the proper salt
command prepending sudo and appending --config-dir.

Examples:

• salt-wrapper salt-call --local test.ping
• salt-wrapper salt '*' state.highstate

The map is stored in /usr/local/etc/salt-wrapper.conf
as a JSON document containing a roots array, each entry
an object with config and states property:

{
    "roots": [
        {
            "config": "/usr/local/etc/salt-woodscloud",
            "states": "/opt/woodscloud-operations"
        },
        {
            "config": "/usr/local/etc/salt",
            "states": "/opt/nasqueron-operations"
        }
    ]
}

Test Plan:
Run example salt and salt-call commands from /opt/nasqueron-operations
and /usr/local/etc/salt-woodscloud

Reviewers: Sandlayth, dereckson

Reviewed By: dereckson

Subscribers: xcombelle

Differential Revision: https://devcentral.nasqueron.org/D1023