There are a couple of drivers that swallow errors that may occur in
their Put() implementation.
This changes the signature of (*Driver).Put for all the drivers implemented.
Signed-off-by: Vincent Batts <vbatts@hashbangbash.com>
To avoid an expensive call to archive.ChangesDirs() which walks two directory
trees and compares every entry, archive.ApplyLayer() has been extended to
also return the size of the layer changes.
Docker-DCO-1.1-Signed-off-by: Josh Hawn <josh.hawn@docker.com> (github: jlhawn)
