kubelet: add --runonce flag, exits after starting pod from the manifest
kubelet: add basic test for runonce
Merge pull request #1534 from proppy/kubelet-noonce

kubelet: add --runonce flag
minor comment change for grammar/consistency across v1beta* packages
Merge pull request #1588 from meirf/consistent-grammar-conforms-usage

minor comment change for grammar/consistency across v1beta* packages