libdcp, branch bv2.1-verify

Fix strange crash in verify().

2021-01-20T22:34:54Z

This appears to be necessary to stop the first write to state.subtitle_language from segfaulting. It looks like the optional<> is in some uninitialised / indeterminate state. I could only reproduce this crash when running verify() from DoM, not from the `dcpverify` tool. And some simple test programs suggest that even doing State state; should call the constructors of anything in State.

I don't think we need BOOST_NO_CXX11_SCOPED_ENUMS any more.

2021-01-20T22:34:37Z

Cleanup: more test naming tweaks.

2021-01-20T11:15:04Z

Tidy up some test names.

2021-01-20T10:18:26Z

Cleanup: rename some check_ prefixes to verify_.

2021-01-19T23:54:22Z

Cleanup: some more use of initialiser lists.

2021-01-19T23:41:09Z

VerificationNote message tidying.

2021-01-19T23:31:41Z

Tidy up parameters in VerificationNote.

2021-01-19T22:36:27Z

Cleanup: now have using namespace boost::filesystem.

2021-01-19T19:34:34Z

Fix tests to actually check the results in several cases.

2021-01-19T19:32:18Z