Added AND finished successfully the work on the config file. Perfect with comments and stuff and a in-game config pane. that's a new feature. that's so cool!

src/main/java/de/skate702/craftingkeys/config/ConfigGui.java

@@ -0,0 +1,50 @@
+package de.skate702.craftingkeys.config;
+
+import cpw.mods.fml.client.config.DummyConfigElement;
+import cpw.mods.fml.client.config.GuiConfig;
+import cpw.mods.fml.client.config.IConfigElement;
+import de.skate702.craftingkeys.CraftingKeys;
+import net.minecraft.client.gui.GuiScreen;
+import net.minecraftforge.common.config.ConfigElement;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * Custom Config Gui for Mod Options inside of Minecraft.
+ */
+public class ConfigGui extends GuiConfig {
+    public ConfigGui(GuiScreen parent) {
+        super(parent, getConfigElements(),
+                CraftingKeys.MODID, false, false, CraftingKeys.NAME);
+
+    }
+
+    /**
+     * Generates Config Entires based on the main config file.
+     *
+     * @return A List of IConfigElement-Items, ready to add to the gui.
+     */
+    private static List<IConfigElement> getConfigElements() {
+        List<IConfigElement> list = new ArrayList<IConfigElement>();
+
+        list.add(categoryElement(Config.categoryKeys, Config.categoryKeys, "de.skate702.craftingkeys.keys"));
+        list.add(categoryElement(Config.categoryOther, Config.categoryOther, "de.skate702.craftingkeys.other"));
+
+        return list;
+    }
+
+    /**
+     * Automatically generates category elements for config categories.
+     *
+     * @param category    the given category string (from the config file)
+     * @param name        the name of the category
+     * @param tooltip_key a lang-string, must have tooltip available under .tooltip
+     * @return Returns a IConfigElement ready to add to the list of elements
+     */
+    private static IConfigElement categoryElement(String category, String name, String tooltip_key) {
+        return new DummyConfigElement.DummyCategoryElement(name, tooltip_key,
+                new ConfigElement<java.util.List<cpw.mods.fml.client.config.IConfigElement>>
+                        (Config.configFile.getCategory(category)).getChildElements());
+    }
+}