dimensions the f90 MPI bindings should support (they are strongly
typed, and the number of dimensions of choice arguments must be
specified -- it cannot be arbitrary). The default is four.
Note that even though increasing this value has essentially a linear
effect on the code, the multiplier constant is fairly large (only a
small number of functions have 2 choice buffers, so the exponential
factor is relatively small). Increasing this value increases the
amount of time f90 compilers will spend compiling src/mpi/f90/mpi.f90
(some compilers will crash if it is too big).
This commit was SVN r5268.
