convert url of bilibili.com to embedded video element.
##Usage var bili_convert = require('bilibili-embed-convert');
//Create object
var bili_video = new bili_convert(url);
var bili_video_num = new bili_convert(av_number);
var bili_video_num_page = new bili_convert(av_number, page_number);
//Generate embedded code
var flash = bili_video.flashAddr();
var embedded = bili_video.embedAddr();
var embedded_size = bili_video.embedAddr(height, width);