* General test improvements.
* Adjust tests to older docker-py versions.
* docker_swarm_server_info: work around problems with older docker-py versions
* Bump minimal docker-py version for options network_filters and disk_usage.
* More general test improvements.
* Correct usage of docker_image.
* Put files into output directory.
* Speed up test.
* Remove old check.
* Add source option.
* Split force parameter into force_source, force_absent and force_tag.
* Move all build-related options into a suboption called build.
* Add changelog.
