Enhancements
- Add support for Docker `1.10` or newer which introduces new image format
- The `--from-layer` argument can take now numeric value which specifies how many layers should be squashed.
- Temporary directories are now removed in case of failure, see 44.
- Added `--development`, `-d` switch to enable development mode. Currently this enables full stacktraces and does not remove the temporary directories after failure.
Known issues
- In case you want to squash an image containing missing layers (see `docker history IMAGE_ID` to confirm) most probably you'll need to specify numeric value to the `--from-layer` argument which says how many layer you want to squash. It's impossible to reference a missing layer in other way because these layers do not have populated IDs.
- The `layers` sub-command doesn't work (yet)