mvcc: don't allocate keys when computing Revisions
mvcc: don't allocate keys when computing Revisions

glevand/coreos--etcd,mqliang/etcd,heyitsanthony/etcd,mkumatag/etcd,mqliang/etcd,ajityagaty/etcd,fanminshi/etcd,mkumatag/etcd,YuleiXiao/etcd,bdarnell/etcd,whuwxl/etcd,xiang90/etcd,sebrandon1/etcd,etcd-io/etcd,akauppi/etcd,cockroachdb/etcd,mickep76/etcd,fanminshi/etcd,dannysauer/etcd,bluebreezecf/etcd,rnaveiras/etcd,sinsharat/etcd,YuleiXiao/etcd,cockroachdb/etcd,joshix/etcd,vimalk78/etcd,li-ang/etcd,heyitsanthony/etcd,visheshnp/etcd,mkumatag/etcd,li-ang/etcd,glevand/coreos--etcd,coreos/etcd,a-robinson/etcd,vimalk78/etcd,gyuho/etcd,gyuho/etcd,a-robinson/etcd,sinsharat/etcd,bluebreezecf/etcd,rnaveiras/etcd,lorneli/etcd,etcd-io/etcd,ajityagaty/etcd,ajityagaty/etcd,whuwxl/etcd,lorneli/etcd,bdarnell/etcd,mickep76/etcd,rnaveiras/etcd,coreos/etcd,akauppi/etcd,sebrandon1/etcd,joshix/etcd,xiang90/etcd,etcd-io/etcd,visheshnp/etcd,dannysauer/etcd,mqliang/etcd