Fails to read 4 instances from Maros-Meszaros QP benchmark

[gdalle]

Here are the four culprits, diagnosed with MathOptBenchmarkInstances.jl (soon to be registered):

julia> using MathOptBenchmarkInstances

julia> for name in ["EXDATA", "QFORPLAN", "QGFRDXPN", "VALUES"]
           @info name
           try
               read_instance(MarosMeszaros, name)
           catch e
               @show e
           end
       end
[ Info: EXDATA
e = ErrorException("Unknown column -10.")
[ Info: QFORPLAN
e = ErrorException("Duplicate row name DEDO3 at line 6")
[ Info: QGFRDXPN
e = ArgumentError("cannot parse \"PEE\" as Float64")
[ Info: VALUES
e = ErrorException("Unknown column 10.")