修改主题不能有二级目录的bug
Adjust style for autocomplete
Set thumbnail from content & make imgs 100% width

1. Use the last inserted image in content as thumbnail for product,
info and news
2. make the images in content have 100% width for info and product
上传theme修改为theme，2根据输入名称生成主题名称
修改theme.metadata件 1 上传主题的时候如果没有.metadata则生成 2
原来版本是写死的，现在是从.medata中读取
Refactor album_insert_widget

1. add upload and refresh functions
2. async reload image list when refresh or change the album
3. split the html and js