stop trying to build libpnetcdf.a from test directory

git-svn-id: https://svn.mcs.anl.gov/repos/parallel-netcdf/trunk@1632 c368ceb8-fd28-0410-a457-e46ee1d7cd4a
ensure make ptest run MPI programs one after another when users try to run make in parallel

git-svn-id: https://svn.mcs.anl.gov/repos/parallel-netcdf/trunk@1633 c368ceb8-fd28-0410-a457-e46ee1d7cd4a
stop trying to build libpnetcdf.a from examples directory

git-svn-id: https://svn.mcs.anl.gov/repos/parallel-netcdf/trunk@1634 c368ceb8-fd28-0410-a457-e46ee1d7cd4a