Added basic (and functional!) Login screen

Metadata now ignores the Forge part of the Minecraft version String

src/main/java/eu/crushedpixel/replaymod/online/authentication/AuthenticationHandler.java

@@ -0,0 +1,58 @@
+package eu.crushedpixel.replaymod.online.authentication;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
+
+import net.minecraft.client.Minecraft;
+import eu.crushedpixel.replaymod.ReplayMod;
+import eu.crushedpixel.replaymod.api.client.ApiException;
+import eu.crushedpixel.replaymod.reflection.MCPNames;
+
+public class AuthenticationHandler {
+
+	public static final int SUCCESS = 1;
+	public static final int INVALID = 2;
+	public static final int NO_CONNECTION = 3;
+	
+	private static Minecraft mc = Minecraft.getMinecraft();
+
+	private static String authkey = null;
+
+	public static boolean isAuthenticated() {
+		return authkey != null;
+	}
+
+	public static int authenticate(String username, String password) {
+		try {
+			authkey = ReplayMod.apiClient.getLogin(username, password).getAuthkey();
+			return SUCCESS;
+		} catch(ApiException e) {
+			return INVALID;
+		} catch(Exception e) {
+			return NO_CONNECTION;
+		}
+	}
+
+	private static final List<String> PREMIUM_USERS = new ArrayList<String>() {
+		{
+			add("Ender_Workbench");
+			add("oleoleMC");
+			add("Johni0702");
+			add("Rafessor");
+			add("bluffamachuck");
+			add("Panguino");
+			add("SixteenBy16");
+		}
+	};
+	
+	private static boolean isPremiumUsername(String username) {
+		//TODO: API check with the website
+		return (PREMIUM_USERS.contains(username) || MCPNames.env.isMCPEnvironment());
+	}
+
+	private static boolean isPremiumUUID(String uuid) {
+		//TODO: API check with the website
+		return false;
+	}
+}