Fixing and upgrading next step and reply handlers. + minor fixes

Rename telebot package to pytelegrambotapi becouse lib named telebot exists and it raising many errors

Add methods:
|     register_for_reply_by_message_id,
|     register_next_step_handler_by_chat_id,
|     clear_reply_handlers,
|     clear_reply_handlers_by_message_id

examples/step_example.py

@@ -4,12 +4,12 @@ This Example will show you how to use register_next_step handler.
 """
 import time
 
-import telebot
-from telebot import types
+import pytelegrambotapi
+from pytelegrambotapi import types
 
 API_TOKEN = '<api_token>'
 
-bot = telebot.TeleBot(API_TOKEN)
+bot = pytelegrambotapi.TeleBot(API_TOKEN)
 
 user_dict = {}