ZFS-backed block devices may contain just the bare device name and
not have extra options like `,size=foo`, `,format=qcow2` etc. This
breaks an assumption in existing regex (which expects a comma).
Support such device strings and add a couple of testcases to validate.
* Fresh branch to try this again
* Fix typo
* Fix sanity error
* Redid some tests, not sure if this works...
* Re-fixed documentation
* Fixed linter
* Update layout
* Processed feedback
* Processed feedback
* Added check_mode
* Run test with check mode
* Fix layout
* Fix more layout
* Fixed last sanity errors (for now)
* Check mode is not a module arg..
* Fix sanity-error
* Reworked check_mode and adapted tests
* Added extra test to also run through remove logic, added message for check_mode to show output is different, grabbed magicmock from different library to fix py2 errors
* Remove unused function
* Processed feedback
* Processed feedback
* Processed feedback
