Change logic to auto-rev for latest_release and sticky branch.
Change logic to auto-rev for latest_release and sticky branch.

Also some cleanup and fixing so we don't create unnecessary ebuilds.
I noticed that both the latest release and stable release code
were trying to rev the same branch whenever we moved to a new stable
version.  It was harmless before but now that we're pushing this as
stable we want exactly to have the minimum number of revs that are
correct

Change-Id: I9f834d35be8e85c27ab0505ec81637f9a3c27b88

BUG=
TEST=Unittests and mocked in my own directory by creating new stable
branch.

Review URL: http://codereview.chromium.org/6025012

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