(MCO-181) Add --[no-]daemonize flag to mcollectived

Adds the daemonize flag. This flag will override the value defined in
the config file allowing init scripts etc to tell mcollectived whether
it should daemonize or not.
Merge pull request #202 from ploubser/mco-181

(MCO-181) Add --[no-]daemonize flag to mcollectived