per object, in line with the functionality as it was in Varnish 3.0.

esi-included requests don't need to know about it.

passes down to parents VDP stack.

Always close all the VDPs.

Give ESI subrequests a ReqAcct.

Make the bodycount in ReqAcct only the actual body, not including
transmission overhead (such as chunked encoding)

already in the l%d log records