Example crash for #301

running `examples/FEvoRslab/runFevorSlab.sh` results in a crash.

This commits an example which prints information fron the 5th
distribuion. Distribution before first time step is good, Distribution
after step has `-NaN` for the cAxis vector.

Crashes on second time step. Error code is:

[0]PETSC ERROR: enthalpyAndDrainageStep() line 458 in
"unknowndirectory/"/home/joseph/PISM/pism/src/base/iMenthalpy.cc
[0]PETSC ERROR: energyStep() line 86 in
"unknowndirectory/"/home/joseph/PISM/pism/src/base/iMenergy.cc
[0]PETSC ERROR: step() line 748 in
"unknowndirectory/"/home/joseph/PISM/pism/src/base/iceModel.cc
[0]PETSC ERROR: run() line 908 in
"unknowndirectory/"/home/joseph/PISM/pism/src/base/iceModel.cc
[0]PETSC ERROR: main() line 84 in
"unknowndirectory/"/home/joseph/PISM/pism/src/pismr.cc
--------------------------------------------------------------------------
MPI_ABORT was invoked on rank 0 in communicator MPI_COMM_WORLD
with errorcode 1.

NOTE: invoking MPI_ABORT causes Open MPI to kill all MPI processes.
You may or may not see output from other processes, depending on
exactly when Open MPI kills them.
--------------------------------------------------------------------------