Controller类增加batchValidate属性 validate方法增加batch参数，用于设置是否批量验证

异常类改进

library/think/exception/ValidateException.php

@@ -13,4 +13,20 @@ namespace think\exception;
 
 class ValidateException extends \RuntimeException
 {
+	protected $error;
+
+	public function __construct($error)
+	{
+		$this->error = $error;
+	}
+
+    /**
+     * 获取验证错误信息
+     * @access public
+     * @return array|string
+     */
+	public function getError()
+	{
+		return $this->error;
+	}	
 }