libdcp/test/ref, branch combine

Use the read in when the Reel was created from XML (if appropriate)

2020-09-09T20:41:52Z

when writing it out again, rather than creating a new one each time. Also there is the associated test churn here from removing a call to make_uuid().

Fix up some tests.

2020-07-12T13:37:13Z

Hopefully make all tests stable enough to be run with --random,

2020-07-11T19:11:48Z

stopping test reference churn.

Fix test now that Atmos asset ID is correctly read from the MXF.

2020-06-19T11:28:21Z

Add test data missing from previous.

2020-03-08T22:16:24Z

Fix syntax of ContentVersion/Id in the reference.

2019-12-22T00:21:00Z

Fix unit tests after CPL root namespace fix.

2019-09-08T00:47:26Z

Accept that and are optional, and account for this in tests.

2019-03-18T00:29:47Z

Also fix tests to reflect no longer being filled in with a default value.

And corresponding test updates.

2019-03-12T12:05:37Z

Update tests for previous.

2019-03-12T11:53:04Z