Support forum threads

[Jay2k1]

According to the docs, in order to create a forum thread, you only have to supply an additional thread_name field in the JSON (and use a forum channel webhook URL).

I have tried it by just adding a getter and a setter for it in webhook.inc like so:

	public bool GetThreadName(char[] buffer, int maxlength) {
		return this.GetDataString("thread_name", buffer, maxlength);
	}
	
	public void SetThreadName(char[] threadName) {
		this.UpdateDataObject("thread_name", json_string(threadName));
	}

This worked fine to create a thread. I have not tried using the new code on a regular channel webhook though.

BTW, I found out that the thread_name has a maximum length of 100 characters. If you supply a longer title, it gets truncated.

[Rushaway]

json_string is not defined in this include.
Could you provde a test plugin with these function ?