Merge pull request #105 from ralphtheninja/master

callbacks for mkdir and unlink also return response object
joyent/node-manta#110 muntar should retry files on a 500
lint cleanup
joyent/node-manta#108 mlogin(1) should validate input object before creating job
joyent/node-manta#109 mlogin(1) should print diagnostics on a failed or retried job