O1.3: Implement bridges with pluggable transport HTTPT support.

HTTPT is a promising new pluggable transport designed to hide traffic behind HTTPS servers. HTTPT has specific benefits for the case of making Tor more accessible to users in China; specifically that it is immune to replay attacks, which protects it against China’s active probing; it uses existing web servers, so that it’s harder for censors to discover; it requires minimal overhead; and it relies on TLS, a popular protocol, making it much more difficult for censors to block outright. In this Activity we will make Tor Browser and HTTPT work together before pushing for more users in the target region and launching it in Tor Browser.