新功能: 功能优化: 1. [进度条拖动速度及展示效果](https://github.com/kkkunny/bilitv/pull/37/commits/18fa634b746d54ad796551dade4c6346bc3a547f) 2. [音频加载使用备份链接](https://github.com/kkkunny/bilitv/pull/37/commits/849410d554193f7e8e929458f8284837deb68885) Bug Fixes: 1. [拖动进度条不会重置弹幕墙](https://github.com/kkkunny/bilitv/pull/37/commits/a2cb49eeddbca1b20cedbea364a12a3de7aef8b4) 2. [拖动进度条超出进度范围](https://github.com/kkkunny/bilitv/pull/37/commits/2b4208172e5abc11ff77c354d30a730e99f8d5fe)