bawollf and I started hacking on this at the hackathon:
- rMW4feb2ac7f222: Remove unused 'XMPGetInfo' and 'XMPGetResults' hooks
- rMWb97c105515c9: XMP: Throw generic exceptions instead of MWException
- rMW54a912c5e9b0: XMP: Use structured logging instead of wfDebugLog
Dependencies left are wfTimestamp and wfSuppressWarnings/wfRestoreWarnings.