Better error messages when trying to use MPI without a compatible binary

[simonbyrne]

This isn't very helpful:

[simonbyrne]

I guess the solution would be to get rid of the conditional here:

HDF5.jl/src/drivers/drivers.jl

Line 92 in 259763f

HDF5.has_parallel() && include("mpio.jl")

[mkitti]

Maybe we should turn it into and if ... else. If we don't have MPIO, we include another file that returns an error if someone tries to use MPI?

[simonbyrne]

It should throw an error here:

HDF5.jl/src/drivers/mpio.jl

Lines 43 to 48 in 0120cb2

	function set_driver!(fapl::Properties, mpio::MPIO)
	HDF5.has_parallel() || error(
	"HDF5.jl has no parallel support." *
	" Make sure that you're using MPI-enabled HDF5 libraries, and that" *
	" MPI was loaded before HDF5." *
	" See HDF5.jl docs for details."