Example to test pkg/matrix

Instructions for building:

1) mkdir build
2) cd build
3) run genmake with: -mods=../code and -enable=matrix
e.g.,
../../../tools/genmake2  "-mods=../code" "-optfile=../../../tools/build_options/darwin_ppc_xlf_spk" "-enable=matrix"

4) make depend
5) make

Instructions for running:

1) mkdir run
2) cd run
3) cp -p ../input/* .
4) ./mitgcmuv > output.txt

Results:

compare with results/output.txt

