Skip in report when OAD is invalid

[Relequestual]

When running the report generator against a repo with quite a history, it's probably to be expected that the OAD will be invalid at some commits. Someone made an error and committed it, then released and fixed it and committed again. Not everyone will do an interactive rebase to remove mistakes, especially if they are pushed all together.

As such, it's difficult to generate the report when a repo contains many errors in its history.

[daveshanley]

When all OAD's are invalid? or just one of them in the history?

[Relequestual]

Any individual ones in the history are invalid, should be skipped.

I've seen this a lot recently where the OADs were comitted in a broken state.

It would be good to just ignore those commits. One hopes the next commit fixes it, but that's not always the case.