New release of PnetCDF version 1.12.3

[Wei-Keng Liao]

Hello to the PnetCDF community,

The new release of PnetCDF version 1.12.3 is now available for downloading in
https://parallel-netcdf.github.io/wiki/Download.html

Below is a list noticeable changes from the previous version.
* Improve performance when nonblocking requests contain more than one record.
* Revise the definition of "difference ratio" used in utility programs
  cdfdiff and ncmpidiff to formula |x - y| / max(|x|, |y|)
* All PnetCDF I/O hints are now correctly set in the inquired MPI info
  object returned by API ncmpi_inq_file_info().
* Fix a bug in utility program ncvalidator for the case when there is no
  record written, but both fixed-size and record variables are defined.
* Fix configure bug of setting environment variable SEQ_CC to the
  sequential CC extracted from MPICC.

Detailed changes from the previous release can be found in
https://github.com/Parallel-NetCDF/Parallel-NetCDF.github.io/blob/master/Release_notes/1.12.3.md

Please report problems encountered to this mailing list or create
github issues at https://github.com/Parallel-NetCDF/PnetCDF

Best regards,

Wei-keng Liao