Add client-side user ignore list

This commit adds a client-side per-server ignore list.
* Whispers and talk from an ignored user is hidden
* Ignored users cannot join your tables
* Ignored users tables are hidden

Mage.Client/src/main/java/mage/client/chat/LocalCommands.java

@@ -0,0 +1,65 @@
+package mage.client.chat;
+
+import mage.client.MageFrame;
+import mage.client.SessionHandler;
+import mage.client.util.IgnoreList;
+import mage.interfaces.callback.ClientCallback;
+import mage.view.ChatMessage;
+
+import java.text.DateFormat;
+import java.util.Date;
+import java.util.Optional;
+import java.util.StringTokenizer;
+import java.util.UUID;
+
+public class LocalCommands {
+
+    private static final DateFormat timeFormatter = DateFormat.getTimeInstance(DateFormat.SHORT);
+
+    /**
+     * Handler for commands that do not require server interaction, i.e settings etc
+     * @param chatId
+     * @param text
+     * @return true if the command was handled locally, else false
+     */
+    public static boolean handleLocalCommands(UUID chatId, String text) {
+        final StringTokenizer st = new StringTokenizer(text.trim());
+        final int tokens = st.countTokens();
+        if (tokens == 0) {
+            return false;
+        }
+
+        final String serverAddress = SessionHandler.getSession().getServerHostname().orElseGet(() -> "");
+        Optional<String> response = Optional.empty();
+
+        switch (st.nextToken()) {
+            case "/ignore":
+            case "\\ignore":
+                final String ignoreTarget = tokens > 1 ? st.nextToken() : "";
+                response = Optional.of(IgnoreList.ignore(serverAddress, ignoreTarget));
+                break;
+            case "/unignore":
+            case "\\unignore":
+                final String unignoreTarget = tokens > 1 ? st.nextToken() : "";
+                response = Optional.of(IgnoreList.unignore(serverAddress, unignoreTarget));
+                break;
+            // TODO: move profanity settings to here
+            default:
+                break;
+        }
+
+        if (response.isPresent()) {
+            displayLocalCommandResponse(chatId, response.get());
+            return true;
+        }
+
+        return false;
+    }
+
+    private static void displayLocalCommandResponse(UUID chatId, String response) {
+        final String text = new StringBuilder().append("<font color=yellow>").append(response).append("</font>").toString();
+        ClientCallback chatMessage = new ClientCallback("chatMessage", chatId,
+                new ChatMessage("", text, timeFormatter.format(new Date()), ChatMessage.MessageColor.BLUE));
+        MageFrame.getInstance().processCallback(chatMessage);
+    }
+}