[REQUEST] HttpSignaling should be fully asynchronous

[kevinfoley]

The HttpWebRequest operations in HttpSignaling are all synchronous, meaning they will lock the current thread until completed. Currently, HttpSignaling is only partially threaded. HTTPPooling() runs in a separate thread, but other functions in the class can be called from the main thread. For example, SendAnswer() is called from the main thread in Broadcast. This can cause Unity to freeze and become unresponsive if the signaling server is slow to respond to the request.

If HttpWebRequest used asynchronous networking functions, such as those provided by Unity's UnityWebRequest class, requests would never lock the main thread.

[karasusan]

@kevinfoley Right, it should be fixed. Thanks.

[karasusan]

memo: URS-380