Add Java 8 compatibility

As a result of the Kotlin port, using Java 11 becomes less important.
Java 8 is still fairly widespread, so I think supporting it is still
worthwhile.

README.md

@@ -12,7 +12,7 @@ released in late 2009.
 
 Building OpenRS2 requires the following pieces of software:
 
-* [Java Development Kit][jdk] (version 11)
+* [Java Development Kit][jdk] (version 8 or later)
 * [Apache Maven][maven] (version 3.3.9 or later)
 
 ### Non-free components

deob/src/main/java/dev/openrs2/deob/Deobfuscator.kt

@@ -83,7 +83,7 @@ class Deobfuscator(private val input: Path, private val output: Path) {
         glUnpacker.remap(create(glUnpacker, "unpacker_"))
 
         // bundle libraries together into a common classpath
-        val runtime = ClassLoader.getPlatformClassLoader()
+        val runtime = ClassLoader.getSystemClassLoader()
         val classPath = ClassPath(
             runtime,
             dependencies = listOf(),

pom.xml

@@ -5,7 +5,7 @@
   <parent>
     <groupId>dev.openrs2</groupId>
     <artifactId>openrs2-parent</artifactId>
-    <version>1.0.7</version>
+    <version>1.0.8</version>
   </parent>
 
   <artifactId>openrs2</artifactId>
@@ -70,7 +70,7 @@
       <dependency>
         <groupId>dev.openrs2</groupId>
         <artifactId>fernflower</artifactId>
-        <version>1.0.1</version>
+        <version>1.0.2</version>
       </dependency>
       <dependency>
         <groupId>dev.openrs2</groupId>
@@ -80,7 +80,7 @@
       <dependency>
         <groupId>dev.openrs2</groupId>
         <artifactId>pack200</artifactId>
-        <version>1.0.1</version>
+        <version>1.0.2</version>
       </dependency>
       <dependency>
         <groupId>org.ow2.asm</groupId>