feat(history): 新增特码冷热查询功能 — 选定某一期向前y期判定冷热号

在history页面添加「特码冷热」按钮，用户可选择指定期号并设定向前期数
系统统计该期特码在向前范围内的出现频率，与平均值对比判定冷/温/热号

application/admin/view/history/index.html

@@ -17,6 +17,7 @@
                         <a href="javascript:;" class="btn btn-success btn-sumchart" title="{:__('Sum Chart')}"><i class="fa fa-line-chart"></i> {:__('Sum Chart')}</a>
                         <a href="javascript:;" class="btn btn-warning btn-consecutive" title="{:__('Consecutive')}"><i class="fa fa-link"></i> {:__('Consecutive')}</a>
                         <a href="javascript:;" class="btn btn-default btn-tailnums" title="{:__('Tail Numbers')}"><i class="fa fa-list-ol"></i> {:__('Tail Numbers')}</a>
+                        <a href="javascript:;" class="btn btn-danger btn-specialhotcold" title="{:__('Special Hot/Cold')}"><i class="fa fa-fire"></i> {:__('Special Hot/Cold')}</a>
 <!--                        <a href="javascript:;" class="btn btn-success btn-dashboard" title="{:__('Dashboard')}"><i class="fa fa-tachometer"></i> {:__('Dashboard')}</a>-->
 <!--                        <a href="javascript:;" class="btn btn-success btn-add {:$auth->check('history/add')?'':'hide'}" title="{:__('Add')}" ><i class="fa fa-plus"></i> {:__('Add')}</a>-->
                     </div>