userpage: change email (+ confirmation)

edit/add button added for email address. Confirmation works too.

lang/admin/zh-hans.json

@@ -18,7 +18,6 @@
         "create": "创建",
         "apply": "申请",
         "delete": "删除",
-        "add": "添加",
         "select": "选择",
         "name": "名称",
         "date": "日期",
@@ -47,7 +46,6 @@
         "conditionals": "条件性条款",
         "preview": "预览",
         "reset": "重设",
-        "edit": "编辑",
         "donate": "捐助",
         "contactThrough": "联系方式：",
         "extendExpiry": "延长有效期",