Here's a first cut at a patch.  It's really just an update of Victor's patch to #4591 (done with his blessing).  I tweaked it slightly; the parsing functions are now O& converter functions.

I also added a reasonable unit test.  Note however that the unit test is only run if you run the test as root.

I don't think this needs any documentation, just a Misc/NEWS entry.

If someone can give me quick turnaround on a review (or two) maybe we can get this in before beta 2 tomorrow.

I'm adding Antoine and MvL as they were in on the earliest known bug of this class.