V1.1

This version adds some minor improvements:

1. Empty folders will not be created
2. Option to not download uploadable folders (such as 'student submission')
3. Ability to set largest file size limit, so that large files will not be downloaded
4. Notification for new announcements

An experimental feature to download files from lecturer's websites is also implemented. It allows one to specify how to parse those pages using json and CSS3 selector. The format is as follows:

{
    "module_code": {
        "folder_name": {
            "page": "url_to_page",
            "selector": "CSS_selector_like_a[href^=\"../lect\"]"
    }
}

Currently very few courses are available for this feature. The json is stored on https://gist.github.com/yyjhao/5895119 and can be synced in the application. Suggestions are welcomed.