[API] Add command to initialize shared edits dir.
[API] Add command to initialize shared edits dir.

Another necessary step for manually enabling HA.

justinhayes/cm_api,cloudera/cm_api,cdapio/cm_api,justinhayes/cm_api,cdapio/cm_api,justinhayes/cm_api,cdapio/cm_api,cloudera/cm_api,cdapio/cm_api,cloudera/cm_api