Bump up the maximum line size for lines in the ptop file, and make errors in the ptop file immediately fatal - we were somehow getting into a state where the istream for the file was returning !eof, but reading data from it got only empty strings.
Bump up the maximum line size for lines in the ptop file, and make
errors in the ptop file immediately fatal - we were somehow getting
into a state where the istream for the file was returning !eof, but
reading data from it got only empty strings.

nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome