Release v2.3.1

This version is based on Valgrind-3.17.0.

### Added
 - [EXPERIMENTAL] verrou_dd_syncho
	- Enable temporal delta-debug
	- Enable delta-debug for python code
 - checkdenorm back-end
        - The option --rounding-mode=ftz enable mode flush to zero
 - delta-debug improvments
	- Options with cmd options and env variables.
	- Add symlink FullPerturbation and NoPerturbation
	- Use relative path to print delta-debug progress
	- Add --cache option
	- Add heuristics to improve delta-debug (--rddmin-heuristics-cache= and --rddmin-heuristics-rep= options)
	- Add option --res-with-all-samples to be able to compare estimator between ddmin-*
	- Add parallelism (for samples and dichotomy)

### Changed
	- The option --demangle=no is no more required for --gen-exclude, --exclude, --gen-source, --source  options  and so for the delta-debug process
	- License change : The verrou backends and python tools switch to LGPL v2.1. The frontend remains in GPL.

CHANGELOG.md

@@ -1,17 +1,6 @@
 # Change Log
 
-## [UNRELEASED]
-
-This version is based on Valgrind-3.17.0.
-
-### Added
-
-
-### Changed
-
----
-
-## v2.3.0 - 2021-05-31
+## v2.3.1 - 2021-05-31
 
 This version is based on Valgrind-3.17.0.
 

valgrind.diff

@@ -51,7 +51,7 @@ index b86e80220..f67bafdf1 100755
 
  # Process this file with autoconf to produce a configure script.
 -AC_INIT([Valgrind],[3.17.0],[[email protected]])
-+AC_INIT([Valgrind],[3.17.0+verrou-dev],[[email protected]])
++AC_INIT([Valgrind],[3.17.0+verrou-2.3.1],[[email protected]])
  AC_CONFIG_SRCDIR(coregrind/m_main.c)
  AC_CONFIG_HEADERS([config.h])
  AM_INIT_AUTOMAKE([foreign dist-bzip2 subdir-objects])
@@ -174,7 +174,7 @@ index 7d04ee795..a105f0b50 100644
  <!-- valgrind release + version stuff -->
  <!ENTITY rel-type    "Release">
 -<!ENTITY rel-version "3.17.0">
-+<!ENTITY rel-version "3.17.0+verrou-dev">
++<!ENTITY rel-version "3.17.0+verrou-2.3.1">
  <!ENTITY rel-date    "19 Mar 2021">
 
  <!-- where the docs are installed -->