Apply volumes-from before creating volumes

Copies the volumes from the container specified in `Config.VolumesFrom` before
creating volumes from `Config.Volumes`. Skips any preexisting volumes when
processing `Config.Volumes`. Fixes #1351
Skip existing volumes in volumes-from

Removes the error when a container already has a volume that would otherwise
be created by `Config.VolumesFrom`. Allows restarting containers with a
`Config.VolumesFrom` set.
Merge pull request #1496 from xdissent/1351-volumes-from-before-volumes

* Runtime: Apply volumes-from before creating volumes