devserver support for update images from buildbot.
devserver support for update images from buildbot.

Remove implicit sudo from gpt partition packing scripts.

Misc cleanup and fixes included.

Review URL: http://codereview.chromium.org/1633018

fivethreeo/scripts,zhang0137/scripts,trnubo/scripts,fivethreeo/scripts,marineam/coreos-scripts,sigma/coreos-scripts,marineam/coreos-scripts,marineam/coreos-scripts,mischief/scripts,trnubo/scripts,vmware/coreos-scripts,sigma/coreos-scripts,nicescale/scripts,andrejro/coreos--scripts,mischief/scripts,sigma/coreos-scripts,gtank/scripts,andrejro/coreos--scripts,endocode/scripts,gtank/scripts,coreos/scripts,crawford/scripts,zhang0137/scripts,coreos/scripts,glevand/coreos--scripts,glevand/coreos--scripts,crawford/scripts,endocode/scripts,bcwaldon/coreos-scripts,bcwaldon/coreos-scripts,nicescale/scripts,andrejro/coreos--scripts,smilart/scripts,vmware/coreos-scripts,endocode/scripts,mjg59/scripts,bcwaldon/coreos-scripts,smilart/scripts,gtank/scripts,fivethreeo/scripts,crawford/scripts,mjg59/scripts,vmware/coreos-scripts,trnubo/scripts,smilart/scripts,mischief/scripts,zhang0137/scripts,BugRoger/scripts,BugRoger/scripts,nicescale/scripts,BugRoger/scripts,mjg59/scripts