Rebuilt the compose operation in dceconstraints.c.  The
revisions are simpler, and I hope, clearer than the all
previous versions.  Part of the code taken from the
ucar.nc2.Range.compose function.  Modified to handle edge
cases not handled in the Range.compose function.




git-svn-id: https://sub.unidata.ucar.edu/netcdf/trunk@3146 2e3060e4-1ed8-cf1f-9cc2-9586e844a556