Imports of package lease

PathSynopsis
encoding/binaryPackage binary implements simple translation between numbers and byte sequences and encoding and decoding of varints.
errorsPackage errors implements functions to manipulate errors.
github.com/coreos/etcd/lease/leasepbPackage leasepb is a generated protocol buffer package.
github.com/coreos/etcd/storage/backendPackage backend defines a standard interface for etcd's backend storage.
mathPackage math provides basic constants and mathematical functions.
syncPackage sync provides basic synchronization primitives such as mutual exclusion locks.
timePackage time provides functionality for measuring and displaying time.