revise r1929. Cannot compare newname with name->cp as name->cp has been UTF-8 normalized. Also add a note on put_att APIs when one attribute element geerated NC_ERANGE, it continues to add the atrribute to the header object, instead just return the error code

git-svn-id: https://svn.mcs.anl.gov/repos/parallel-netcdf/trunk@1930 c368ceb8-fd28-0410-a457-e46ee1d7cd4a