Merge branch 'api-15' into api-16

# Conflicts:
#	gradle.properties

Author: Yeregorix

src/main/java/org/spongepowered/api/MinecraftVersion.java

@@ -27,6 +27,7 @@
 import org.spongepowered.api.event.server.ClientPingServerEvent;
 import org.spongepowered.api.network.status.StatusResponse;
 
+import java.util.Optional;
 import java.util.OptionalInt;
 
 /**
@@ -44,6 +45,14 @@ public interface MinecraftVersion extends Comparable<MinecraftVersion> {
      */
     String name();
 
+    /**
+     * Gets the id of this Minecraft version.
+     *
+     * @implNote The version id will not be available in a status response.
+     * @return The version id
+     */
+    Optional<String> id();
+
     /**
      * Gets the protocol version of this Minecraft version.
      *

src/main/java/org/spongepowered/api/event/cause/entity/MovementTypes.java

@@ -57,6 +57,8 @@ public final class MovementTypes {
 
     public static final DefaultedRegistryReference<MovementType> PORTAL = MovementTypes.key(ResourceKey.sponge("portal"));
 
+    public static final DefaultedRegistryReference<MovementType> SPECTATOR = MovementTypes.key(ResourceKey.sponge("spectator"));
+
     // SORTFIELDS:OFF
 
     // @formatter:on