expand record variable testing with more scenarios

git-svn-id: https://svn.mcs.anl.gov/repos/parallel-netcdf/trunk@1767 c368ceb8-fd28-0410-a457-e46ee1d7cd4a
add checking using MPI-IO

git-svn-id: https://svn.mcs.anl.gov/repos/parallel-netcdf/trunk@1768 c368ceb8-fd28-0410-a457-e46ee1d7cd4a
add configure option --enable-large-file-test

git-svn-id: https://svn.mcs.anl.gov/repos/parallel-netcdf/trunk@1769 c368ceb8-fd28-0410-a457-e46ee1d7cd4a