Add functions to inspect min/max supported compression levels

as suggested by @svladykin in #80

src/main/java/com/github/luben/zstd/Zstd.java

@@ -421,6 +421,9 @@ public static long trainFromBufferDirect(ByteBuffer samples, int[] sampleSizes,
     public static native int frameHeaderSizeMin();
     public static native int frameHeaderSizeMax();
     public static native int blockSizeMax();
+    /* Min/max compression levels */
+    public static native int minCompressionLevel();
+    public static native int maxCompressionLevel();
 
     /* Convenience methods */
 

src/main/native/jni_zstd.c

@@ -417,3 +417,13 @@ JNIEXPORT jint JNICALL Java_com_github_luben_zstd_Zstd_blockSizeMax
   (JNIEnv *env, jclass obj) {
     return ZSTD_BLOCKSIZE_MAX;
 }
+
+JNIEXPORT jint JNICALL Java_com_github_luben_zstd_Zstd_minCompressionLevel
+  (JNIEnv *env, jclass obj) {
+    return ZSTD_minCLevel();
+}
+
+JNIEXPORT jint JNICALL Java_com_github_luben_zstd_Zstd_maxCompressionLevel
+  (JNIEnv *env, jclass obj) {
+    return ZSTD_maxCLevel();
+}

version

@@ -1 +1 @@
-1.3.7-1
+1.3.7-2