Moved LZ4 to its own class to male LZ4 optional

src/dorkbox/bytes/LZ4Util.kt

@@ -24,6 +24,17 @@ import java.io.InputStream
 import java.security.NoSuchAlgorithmException
 
 object LZ4Util {
+    init {
+        try {
+            Class.forName("net.jpountz.xxhash.XXHashFactory")
+        }
+        catch (e: Exception) {
+            System.err.println("Please add the LZMA library to your classpath, for example: implementation(\"org.lz4:lz4-java:1.8.0\")")
+            throw e
+        }
+
+    }
+
     private val xxHashFactory: ThreadLocal<XXHashFactory> by lazy {
         ThreadLocal.withInitial {
             try {