Various fixes, including:
- We now limit the size of the sparse file (when doing this does not result in less than 20GB of sparse file space) to avoid encroaching on the
reserved_space_for_other_jobs. This is necessary because sparse files do not reclaim free space, so it's is possible for the underlying sparse file to exceed the size of the actual mounted loop device in some cases if this is not done. See https://www.pivotaltracker.com/story/show/165764224 for more. - Better handling of empty logs from Image Plugin (cloudfoundry/guardian#128, thanks @aminjam!)
- More permissive of some docker registries that incorrectly report blob size (https://www.pivotaltracker.com/story/show/166465168)
- Fixes some issues for volume services in rootless mode (https://www.pivotaltracker.com/story/show/164649716)