Fix the website for China

[Blue_Beaker]

I'm a pack maker in China and some pages doesn't work,such as the login button on the download page,and the key reset page
Please fix this.
PS:Most Google services are NOT usable in China, so something like scripts from https://ajax.googleapis.com/ doesnt work in China,too. You can use a mirror library exclusive to China to make sure the website works properly.

[HanFox]

I'm under the impression Cloudflare's CDN works in China, so I've changed the jQuery for the main website to fetch from that instead (although arguably saving it to the webserver would be better).

If you find any other important functions blocked/broken let me know, and, if you can, try and provide a solution you know works.