Added function call and function definition

src/main/java/de/hsrm/compiler/Klang/nodes/FunctionDefinition.java

@@ -0,0 +1,22 @@
+package de.hsrm.compiler.Klang.nodes;
+
+import de.hsrm.compiler.Klang.visitors.Visitor;
+
+public class FunctionDefinition extends Node {
+
+  public String name;
+  public String[] parameters;
+  public Block block;
+
+  public FunctionDefinition(String name, String[] parameters, Block block) {
+    this.name = name;
+    this.parameters = parameters;
+    this.block = block;
+  }
+
+
+  @Override
+  public <R> R welcome(Visitor<R> v) {
+    return v.visit(this);
+  }
+}