Add support for delegating permissions to Sponge.

When Sponge is not installed, behaviour is as before.
Closes #331

config/checkstyle/import-control.xml

@@ -55,6 +55,7 @@
       <allow pkg="org.apache.logging.log4j"/>
       <allow pkg="org.lwjgl"/>
       <allow pkg="io.netty.buffer"/>
+      <allow pkg="org.spongepowered.api" />
     </subpackage>
   </subpackage>
 </import-control>

worldedit-forge/build.gradle

@@ -15,9 +15,14 @@ apply plugin: 'forge'
 
 dependencies {
     compile project(':worldedit-core')
+    compile 'org.spongepowered:spongeapi:2.1-SNAPSHOT'
     testCompile group: 'org.mockito', name: 'mockito-core', version:'1.9.0-rc1'
 }
 
+repositories {
+    maven { url ="https://repo.spongepowered.org/maven" }
+}
+
 minecraft {
     ext.forgeVersion = "11.14.0.1281"
     version = "1.8-$forgeVersion-1.8"

worldedit-forge/src/main/java/com/sk89q/worldedit/forge/ForgePermissionsProvider.java

@@ -23,6 +23,7 @@ import net.minecraft.command.ICommand;
 import net.minecraft.entity.player.EntityPlayerMP;
 import net.minecraft.world.WorldSettings.GameType;
 import net.minecraftforge.fml.common.FMLCommonHandler;
+import org.spongepowered.api.entity.player.Player;
 
 public interface ForgePermissionsProvider {
 
@@ -49,4 +50,17 @@ public interface ForgePermissionsProvider {
         @Override
         public void registerPermission(ICommand command, String permission) {}
     }
+
+    public static class SpongePermissionsProvider implements ForgePermissionsProvider {
+
+        @Override
+        public boolean hasPermission(EntityPlayerMP player, String permission) {
+            return ((Player) player).hasPermission(permission);
+        }
+
+        @Override
+        public void registerPermission(ICommand command, String permission) {
+
+        }
+    }
 }

worldedit-forge/src/main/java/com/sk89q/worldedit/forge/ForgeWorldEdit.java

@@ -36,6 +36,7 @@ import net.minecraftforge.common.MinecraftForge;
 import net.minecraftforge.event.CommandEvent;
 import net.minecraftforge.event.entity.player.PlayerInteractEvent;
 import net.minecraftforge.fml.common.FMLCommonHandler;
+import net.minecraftforge.fml.common.Loader;
 import net.minecraftforge.fml.common.Mod;
 import net.minecraftforge.fml.common.Mod.EventHandler;
 import net.minecraftforge.fml.common.Mod.Instance;
@@ -60,7 +61,7 @@ import static net.minecraftforge.event.entity.player.PlayerInteractEvent.Action;
 /**
  * The Forge implementation of WorldEdit.
  */
-@Mod(modid = ForgeWorldEdit.MOD_ID, name = "WorldEdit", version = "%VERSION%", acceptableRemoteVersions = "*")
+@Mod(modid = ForgeWorldEdit.MOD_ID, name = "WorldEdit", version = "%VERSION%", acceptableRemoteVersions = "*", dependencies = "after:Sponge")
 public class ForgeWorldEdit {
 
     public static Logger logger;
@@ -116,7 +117,12 @@ public class ForgeWorldEdit {
         this.platform = new ForgePlatform(this);
 
         WorldEdit.getInstance().getPlatformManager().register(platform);
-        this.provider = new ForgePermissionsProvider.VanillaPermissionsProvider(platform);
+
+        if (Loader.isModLoaded("Sponge")) {
+            this.provider = new ForgePermissionsProvider.SpongePermissionsProvider();
+        } else {
+            this.provider = new ForgePermissionsProvider.VanillaPermissionsProvider(platform);
+        }
     }
 
     @EventHandler