Darshan 2.3.1 release

Darshan version 2.3.1 is now available for download.  This release includes several bug fixes and enhancements, including improvements for Cray, IBM Blue Gene, and Linux cluster environments.   One of the most notable new features is that Darshan now supports the MPICH profiling configuration file method for instrumentation, which simplifies installation on some platforms.  This release also includes a new regression testing framework.
The full changelog since 2.3.0:
darshan-2.3.1
=============
* added documentation and example configuration files for using the -profile or $MPICC_PROFILE hooks to add instrumentation to MPICH-based MPI implementations without generating custom wrapper scripts
* Add wrappers for mkstemp(), mkostemp(), mkstemps(), and mkostemps() (reported by Tom Peterka)
* Change OPEN_TIMESTAMP field to report timestamp right before open() is invoked rather than after timestamp after open is completed. NOTE: updated log format version to 2.06 to reflect this change.
* Change start_time and end_time fields in job record to use min and max (respectively) across all ranks
* Fix bug in write volume data reported in file system table in darshan-job-summary.pl (reported by Matthieu Dorier)
* Clean up autoconf test for zlib and make zlib mandatory (reported by Kalyana Chadalavada)
* add –start-group and –end-group notation to Darshan libraries for Cray PE 2.x environment to fix link-time corner cases (Yushu Yao)
* improve y axis labels on time interval graphs in darshan-job-summary.pl (reported by Tom Peterka)
* misc. improvements to darshan-parser –perf output (reported by Shane Snyder)
– indicate which rank was slowest in unique file results
– label I/O vs. meta time more clearly
– include unique file meta time in agg_perf_by_slowest calculation
* added regression test script framework in darshan-test/regression/
– currently support platforms include:
– Linux with static linking and generated compiler wrappers
– Linux with static linking and profiler configuration files
– Linux with dynamic linking and LD_PRELOAD
– Blue Gene/Q with static linking and profiler configuration files
* update darshan-gen-fortran.pl and darshan-gen-cxx.pl to support new library naming conventions in MPICH 3.1.1 and higher
* update documentation to reflect known issues with some versions of MPICH
* Cray platforms: modify darshan-runtime so that link-time instrumentation options are only used when statically linking via Libs.private. (reported by Kalyana Chadalavada)