What do you think of reducing the default number of saved stdout lines
in MPI install sections from 100 to 50?
The main use for saving the stdout in MPI Install is to give context
for when there's stderr output. I think that 50 lines is still much
more than enough; I think that 100 lines has shown to be excessive.
The default for stderr should stay at 100 because a) there usually
isn't much sent to stdout, and b) it's good to keep it semi-large so
that we can see all the compiler warnings.