(MCOP-47) Default yaml values when no specified

The Result class of the mcollective Data module checks the class of
values retrieved from the yaml file; nil values are not accepted.
This fix ensures that values are set to "unknown" or 0 when not
specified.
Merge pull request #30 from parisiale/MCOP-47

(MCOP-47) Set config version to unknown when not specified in yaml