Bump version in preparation of new release

NEWS.txt

@@ -1,7 +1,24 @@
            libSBML NEWS -- History of user-visible changes
 
 ====================================================================
-5.20.4
+5.21.0 (2026-01-09)
+====================================================================
+
+This release further improves the ODE to Reaction converter, 
+improves the ASTNode::derivative function to support all allowed 
+math constructs, and resolves a number of build and stability 
+issues.
+
+====================================================================
+5.20.5 (2025-05-05)
+====================================================================
+
+This release adds support for retrieving / setting notes via Markdown 
+(using the 3rdParty libraries html2md and maddy). Additionally, a 
+number of stability and build issues were resolved.
+
+====================================================================
+5.20.4 (2024-08-07)
 ====================================================================
 
 This is mostly a bug fix release enhancing stability and improving 
@@ -13,7 +30,7 @@ performance when validating models. Main points:
 
 
 ====================================================================
-5.20.2
+5.20.2 (2023-09-21)
 ====================================================================
 
 This is mostly a bug fix release enhancing stability when validating

VERSION.txt

@@ -1 +1 @@
-5.20.5
+5.21.0

configure

@@ -1,7 +1,7 @@
 #! /bin/sh
 # From configure.ac Revision.
 # Guess values for system-dependent variables and create Makefiles.
-# Generated by GNU Autoconf 2.72 for libSBML 5.20.5.
+# Generated by GNU Autoconf 2.72 for libSBML 5.21.0.
 #
 # Report bugs to <libsbml-team@googlegroups.com>.
 #
@@ -759,8 +759,8 @@ MAKEFLAGS=
 # Identity of this package.
 PACKAGE_NAME='libSBML'
 PACKAGE_TARNAME='libsbml'
-PACKAGE_VERSION='5.20.5'
-PACKAGE_STRING='libSBML 5.20.5'
+PACKAGE_VERSION='5.21.0'
+PACKAGE_STRING='libSBML 5.21.0'
 PACKAGE_BUGREPORT='libsbml-team@googlegroups.com'
 PACKAGE_URL='http://sbml.org/Software/libSBML'
 
@@ -1655,7 +1655,7 @@ if test "$ac_init_help" = "long"; then
   # Omit some internal or obsolete options to make the list less imposing.
   # This message is too long to be a string in the A/UX 3.1 sh.
   cat <<_ACEOF
-'configure' configures libSBML 5.20.5 to adapt to many kinds of systems.
+'configure' configures libSBML 5.21.0 to adapt to many kinds of systems.
 
 Usage: $0 [OPTION]... [VAR=VALUE]...
 
@@ -1721,7 +1721,7 @@ fi
 
 if test -n "$ac_init_help"; then
   case $ac_init_help in
-     short | recursive ) echo "Configuration of libSBML 5.20.5:";;
+     short | recursive ) echo "Configuration of libSBML 5.21.0:";;
    esac
   cat <<\_ACEOF
 
@@ -1878,7 +1878,7 @@ fi
 test -n "$ac_init_help" && exit $ac_status
 if $ac_init_version; then
   cat <<\_ACEOF
-libSBML configure 5.20.5
+libSBML configure 5.21.0
 generated by GNU Autoconf 2.72
 
 Copyright (C) 2023 Free Software Foundation, Inc.
@@ -2494,7 +2494,7 @@ cat >config.log <<_ACEOF
 This file contains any messages produced by compilers while
 running configure, to aid debugging if configure makes a mistake.
 
-It was created by libSBML $as_me 5.20.5, which was
+It was created by libSBML $as_me 5.21.0, which was
 generated by GNU Autoconf 2.72.  Invocation command line was
 
   $ $0$ac_configure_args_raw
@@ -3497,19 +3497,19 @@ ac_config_headers="$ac_config_headers src/sbml/common/libsbml-package.h"
 ac_config_headers="$ac_config_headers src/sbml/common/libsbml-namespace.h"
 
 
-LIBSBML_VERSION_NUMERIC=52004
+LIBSBML_VERSION_NUMERIC=52100
 
 
 
 LIBSBML_MAJOR_VERSION=5
 
 
 
-LIBSBML_MINOR_VERSION=20
+LIBSBML_MINOR_VERSION=21
 
 
 
-LIBSBML_REVISION_VERSION=4
+LIBSBML_REVISION_VERSION=0
 
 
 
@@ -29224,7 +29224,7 @@ cat >>$CONFIG_STATUS <<\_ACEOF || ac_write_fail=1
 # report actual input values of CONFIG_FILES etc. instead of their
 # values after options handling.
 ac_log="
-This file was extended by libSBML $as_me 5.20.5, which was
+This file was extended by libSBML $as_me 5.21.0, which was
 generated by GNU Autoconf 2.72.  Invocation command line was
 
   CONFIG_FILES    = $CONFIG_FILES
@@ -29289,7 +29289,7 @@ ac_cs_config_escaped=`printf "%s\n" "$ac_cs_config" | sed "s/^ //; s/'/'\\\\\\\\
 cat >>$CONFIG_STATUS <<_ACEOF || ac_write_fail=1
 ac_cs_config='$ac_cs_config_escaped'
 ac_cs_version="\\
-libSBML config.status 5.20.5
+libSBML config.status 5.21.0
 configured by $0, generated by GNU Autoconf 2.72,
   with options \\"\$ac_cs_config\\"
 

src/sbml/common/libsbml-version.h

@@ -51,7 +51,7 @@
  *
  * A version string of the form "1.2.3".
  */
-#define LIBSBML_DOTTED_VERSION	"5.20.5"
+#define LIBSBML_DOTTED_VERSION	"5.21.0"
 
 
 /**
@@ -62,15 +62,15 @@
  * libSBML is released, making it easy to use less-than and greater-than
  * comparisons when testing versions numbers.
  */
-#define LIBSBML_VERSION		52004
+#define LIBSBML_VERSION		52100
 
 
 /**
  * LIBSBML_VERSION_STRING:
  *
  * The numeric version as a string: version 1.2.3 becomes "10203".
  */
-#define LIBSBML_VERSION_STRING	"52004"
+#define LIBSBML_VERSION_STRING	"52100"
 
 
 LIBSBML_CPP_NAMESPACE_BEGIN