add another configure option for Mira

git-svn-id: https://svn.mcs.anl.gov/repos/parallel-netcdf/trunk@1741 c368ceb8-fd28-0410-a457-e46ee1d7cd4a
add note on what should go to FLAGS for configure command-line options

git-svn-id: https://svn.mcs.anl.gov/repos/parallel-netcdf/trunk@1742 c368ceb8-fd28-0410-a457-e46ee1d7cd4a
just some comments

git-svn-id: https://svn.mcs.anl.gov/repos/parallel-netcdf/trunk@1743 c368ceb8-fd28-0410-a457-e46ee1d7cd4a