Merge branch 'dev/1.1.0' into dev/2.0.0

# Conflicts:
#	api/build.gradle
#	api/src/main/java/com/velocitypowered/api/proxy/connection/Player.java
#	api/src/main/java/com/velocitypowered/api/proxy/player/TabList.java
#	build.gradle
#	proxy/build.gradle
#	proxy/src/main/java/com/velocitypowered/proxy/Velocity.java
#	proxy/src/main/java/com/velocitypowered/proxy/command/CommandNodeFactory.java
#	proxy/src/main/java/com/velocitypowered/proxy/connection/backend/BackendPlaySessionHandler.java
#	proxy/src/main/java/com/velocitypowered/proxy/connection/backend/BungeeCordMessageResponder.java
#	proxy/src/main/java/com/velocitypowered/proxy/connection/backend/VelocityServerConnection.java
#	proxy/src/main/java/com/velocitypowered/proxy/connection/client/ConnectedPlayer.java
#	proxy/src/main/java/com/velocitypowered/proxy/network/packet/clientbound/ClientboundAvailableCommandsPacket.java
#	proxy/src/main/java/com/velocitypowered/proxy/network/packet/clientbound/ClientboundJoinGamePacket.java
#	proxy/src/main/java/com/velocitypowered/proxy/network/packet/clientbound/ClientboundRespawnPacket.java
#	proxy/src/main/java/com/velocitypowered/proxy/network/pipeline/MinecraftDecoder.java
#	proxy/src/main/java/com/velocitypowered/proxy/protocol/MinecraftPacket.java
#	proxy/src/main/java/com/velocitypowered/proxy/protocol/packet/EncryptionResponse.java
#	proxy/src/main/java/com/velocitypowered/proxy/protocol/packet/HeaderAndFooter.java
#	proxy/src/main/java/com/velocitypowered/proxy/protocol/packet/LoginPluginMessage.java
#	proxy/src/main/java/com/velocitypowered/proxy/protocol/packet/PluginMessage.java
#	proxy/src/main/java/com/velocitypowered/proxy/protocol/packet/ServerLogin.java
#	proxy/src/main/java/com/velocitypowered/proxy/protocol/packet/StatusPing.java
#	proxy/src/main/java/com/velocitypowered/proxy/protocol/packet/StatusRequest.java
#	proxy/src/main/java/com/velocitypowered/proxy/tablist/VelocityTabList.java
#	proxy/src/main/java/com/velocitypowered/proxy/tablist/VelocityTabListLegacy.java
#	proxy/src/test/java/com/velocitypowered/proxy/command/CommandManagerTests.java

api/src/main/java/com/velocitypowered/api/event/player/PlayerChannelRegisterEvent.java

@@ -0,0 +1,38 @@
+package com.velocitypowered.api.event.player;
+
+import com.google.common.base.Preconditions;
+import com.velocitypowered.api.proxy.Player;
+import com.velocitypowered.api.proxy.messages.ChannelIdentifier;
+
+import java.util.List;
+
+/**
+ * This event is fired when a client ({@link Player}) sends a plugin message through the
+ * register channel.
+ */
+public final class PlayerChannelRegisterEvent {
+
+  private final Player player;
+  private final List<ChannelIdentifier> channels;
+
+  public PlayerChannelRegisterEvent(Player player, List<ChannelIdentifier> channels) {
+    this.player = Preconditions.checkNotNull(player, "player");
+    this.channels = Preconditions.checkNotNull(channels, "channels");
+  }
+
+  public Player getPlayer() {
+    return player;
+  }
+
+  public List<ChannelIdentifier> getChannels() {
+    return channels;
+  }
+
+  @Override
+  public String toString() {
+    return "PlayerChannelRegisterEvent{"
+            + "player=" + player
+            + ", channels=" + channels
+            + '}';
+  }
+}

api/src/main/java/com/velocitypowered/api/proxy/messages/MinecraftChannelIdentifier.java

@@ -12,7 +12,7 @@ import org.checkerframework.checker.nullness.qual.Nullable;
  */
 public final class MinecraftChannelIdentifier implements ChannelIdentifier {
 
-  private static final Pattern VALID_IDENTIFIER_REGEX = Pattern.compile("[a-z0-9\\-_]*");
+  private static final Pattern VALID_IDENTIFIER_REGEX = Pattern.compile("[a-z0-9/\\-_]*");
 
   private final String namespace;
   private final String name;

api/src/main/java/com/velocitypowered/api/proxy/server/ServerPing.java

@@ -227,6 +227,11 @@ public final class ServerPing {
       return this;
     }
 
+    public Builder clearFavicon() {
+      this.favicon = null;
+      return this;
+    }
+
     /**
      * Uses the information from this builder to create a new {@link ServerPing} instance. The
      * builder can be re-used after this event has been called.

api/src/test/java/com/velocitypowered/api/proxy/messages/MinecraftChannelIdentifierTest.java

@@ -35,6 +35,11 @@ class MinecraftChannelIdentifierTest {
     assertEquals(expected, MinecraftChannelIdentifier.from("velocity:test"));
   }
 
+  @Test
+  void createAllowsSlashes() {
+    create("velocity", "test/test2");
+  }
+
   @Test
   void fromIdentifierThrowsOnBadValues() {
     assertAll(