Merge branch 'jonbob/cime/update-ic-machines-042517' into (PR #1454)

Update PIO_TYPENAME default for LANL IC machine wolf

This PR updates the default PIO_TYPENAME setting for the LANL IC machine to
netcdf. Testing indicates that pnetcdf is much slower for the resolutions we
typically run on this machine.

[BFB]

config/acme/machines/config_pio.xml

@@ -60,6 +60,7 @@
       <value mach="lawrencium-lr3">netcdf</value>
       <value mach="cades">netcdf</value>
       <value mach="grizzly">netcdf</value>
+      <value mach="wolf">netcdf</value>
       <value mpilib="mpi-serial">netcdf</value>
     </values>
   </entry>