Split mod into core, recording, replay, render[todo], paths[todo] and extras[wip] modules

Move everything to com.replaymod package
Add KeyBindingRegistry and SettingsRegistry
Recreate settings GUI with new GUI API and dynamically from SettingsRegistry
Use ReplayFile from ReplayStudio
ReplayHandler is now object oriented
Add GuiOverlay, GuiSlider and GuiTexturedButton to GUI API
Rewrite both overlays to use new GUI API
Fix size capping in vertical and horizontal layout
Allow CustomLayouts to have parents
Fix tooltip rendering when close to screen border
Allow changing of columns in GridLayout

src/main/java/com/replaymod/extras/ReplayModExtras.java

@@ -0,0 +1,44 @@
+package com.replaymod.extras;
+
+import com.replaymod.core.ReplayMod;
+import net.minecraftforge.fml.common.Mod;
+import net.minecraftforge.fml.common.event.FMLInitializationEvent;
+import net.minecraftforge.fml.common.event.FMLPreInitializationEvent;
+import org.apache.logging.log4j.Logger;
+
+import java.util.Arrays;
+import java.util.List;
+
+@Mod(modid = ReplayModExtras.MOD_ID, useMetadata = true)
+public class ReplayModExtras {
+    public static final String MOD_ID = "replaymod-extras";
+
+    @Mod.Instance(MOD_ID)
+    public static ReplayModExtras instance;
+
+    @Mod.Instance(ReplayMod.MOD_ID)
+    private static ReplayMod core;
+
+    private static final List<Class<? extends Extra>> builtin = Arrays.<Class<? extends Extra>>asList(
+            HotkeyButtons.class
+    );
+
+    private Logger logger;
+
+    @Mod.EventHandler
+    public void preInit(FMLPreInitializationEvent event) {
+        logger = event.getModLog();
+    }
+
+    @Mod.EventHandler
+    public void init(FMLInitializationEvent event) {
+        for (Class<? extends Extra> cls : builtin) {
+            try {
+                Extra extra = cls.newInstance();
+                extra.register(core);
+            } catch (Throwable t) {
+                logger.warn("Failed to load extra " + cls.getName() + ": ", t);
+            }
+        }
+    }
+}