add a status filter to get clusters call.
logging and doc fixes.
update rest api docs to include status filter.
check for empty list before accessing first element.
Merge pull request #504 from continuuity/feature/cluster-status-filter

add a status filter to get clusters call.
invoking tar with -h which is consistent between gnu and bsd tar
Merge pull request #518 from continuuity/hotfix/tar-generation

invoking tar with -h which is consistent between gnu and bsd tar
latest ubuntu 12 image
Merge branch 'develop' into feature/resource-joyent
nomenclature update