bump the library version to 0.3.1 and update the release log

build.gradle

@@ -13,7 +13,7 @@ plugins {
 
 ext {
     group = 'com.github.stephengold'
-    version = '0.3.1-SNAPSHOT'
+    version = '0.3.1'
     baseName = "${artifact}-${version}" // for artifacts
     websiteUrl = 'https://github.com/stephengold/jolt-jni'
 }

release-log.md

@@ -1,5 +1,25 @@
 # release log for the jolt-jni project
 
+## Version 0.3.1 released on TBD
+
++ Bugfix:  memory leak in `MassProperties`
++ Added many methods.
++ Added classes and interfaces to the library:
+  + `BroadPhaseLayerInterface`
+  + `ConstBodyCreationSettings`
+  + `ConstBroadPhaseLayerInterface`
+  + `ConstMassProperties`
+  + `ConstObjectLayerPairFilter`
+  + `ConstObjectVsBroadPhaseLayerFilter`
+  + `EAllowedDofs`
+  + `EOverrideMassProperties`
+  + `Mat44`
+  + `Mat44Arg`
+  + `ObjectLayerPairFilter`
+  + `ObjectVsBroadPhaseLayerFilter`
+  + `UVec4`
+  + `UVec4Arg`
+
 ## Version 0.3.0 released on 16 July 2024
 
 + Added a `java.lang.ref.Cleaner` to automatically free native

src/main/native/glue/Jolt.cpp

@@ -192,6 +192,6 @@ JNIEXPORT void JNICALL Java_com_github_stephengold_joltjni_Jolt_unregisterTypes
  */
 JNIEXPORT jstring JNICALL Java_com_github_stephengold_joltjni_Jolt_versionString
   (JNIEnv *pEnv, jclass) {
-    jstring result = pEnv->NewStringUTF("0.3.1-SNAPSHOT");
+    jstring result = pEnv->NewStringUTF("0.3.1");
     return result;
 }