Adding --desc_from_logs option from git cl upload
Adding --desc_from_logs option from git cl upload

TEST=Tested git cl upload --desc_from_logs -m "Message" in http://codereview.chromium.org/3027010/show

Review URL: http://codereview.chromium.org/3048005

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