message: add specialized conversation functions pertaining to threads
diff: @@ -298,7 +298,10 @@ module.exports = function(botkit, config) {
  };
  bot.startConversation = function(message, cb) {
  + botkit.startConversation(this, message, cb);
  + };
  + bot.startConversationInThread = function(message, cb) {
  // make replies happen in a thread
  if (!message.thread_ts) {
  message.thread_ts = message.ts;
  @@ -307,7 +310,11 @@ module.exports = function(botkit, config) {
  };
  bot.createConversation = function(message, cb) {
  + botkit.createConversation(this, message, cb);
  + };
  + bot.createConversationInThread = function(message, cb) {
  + // make replies happen in a thread
  if (!message.thread_ts) {
  message.thread_ts = message.ts;
  }
  @@ -610,7 +617,7 @@ module.exports = function(botkit, config) {
  bot.say(msg, cb);
  };
  - bot.replyWithThread = function(src, resp, cb) {
  + bot.replyInThread = function(src, resp, cb) {
  var msg = {};
  if (typeof(resp) == 'string') {
  