CLSystemAlertController

CLSystemAlertController 封装了系统提示窗口，兼容iOS8.3以下版本。

使用方法：

__weak __typeof(self) weakSelf = self;
[CLSystemAlertController ShowAlertToController:self
                          alertControllerStyle:SystemAlertStyleAlert
                                         title:@"这是标题"
                                       message:@"详细信息"
                             cancelButtonTitle:@"取消"
                        destructiveButtonTitle:@"重点按钮"
                             otherButtonTitles:@[@"第二", @"第三"]
                            clickedButtonBlock:^(NSUInteger index) {
                                weakSelf.indexField.text = [NSString stringWithFormat:@"%d", index];
                            }];
如果共有n个按钮，则：
cancelButton按钮的序号为 0，
destructiveButton按钮的序号为1，
otherButton按钮的序号从为 2 ～ n-1，
如果cancelButtonTitle或者destructiveButtonTitle为nil，则其他按钮的序号向前补位