Re-add PermissionEX handler

Essentials/src/com/earth2me/essentials/perm/PermissionsHandler.java

@@ -92,6 +92,7 @@ public class PermissionsHandler implements IPermissionsHandler {
     public void checkPermissions() {
         // load and assign a handler
         List<Class<? extends SuperpermsHandler>> providerClazz = Arrays.asList(
+                PermissionsExHandler.class,
                 GenericVaultHandler.class,
                 SuperpermsHandler.class
         );

Essentials/src/com/earth2me/essentials/perm/impl/PermissionsExHandler.java

@@ -0,0 +1,16 @@
+package com.earth2me.essentials.perm.impl;
+
+import org.bukkit.Bukkit;
+import org.bukkit.entity.Player;
+
+public class PermissionsExHandler extends AbstractVaultHandler {
+    @Override
+    public boolean canBuild(final Player base, final String group) {
+        return base != null && chat.getPlayerInfoBoolean(base.getWorld().getName(), base, "build", false);
+    }
+
+    @Override
+    public boolean tryProvider() {
+        return super.canLoad() && Bukkit.getPluginManager().getPlugin("PermissionsEx") != null;
+    }
+}