Improve comments in MemoryManager backpressure
CsvParser.Setup is Iced, serializable

Also add String[][] to AutoBuffer
Generify DRemoteTask & MRTask

Pull in log2 fix
Proper dfork/get for MRTask2
Multifile, multinode parse launch

Untested, of course, still trying to get a single file to parse sanely,
just pulling in some of the multi-file support structure