Weirdness with Bot._message_wrapper #627

We have some weirdness and inconsistencies going on with how we use the _message_wrapper in Bot.
Some send_* methods use the @message decorator, others, however, use the _message_wrapper directly. And the way that they use it seems quite frankly, wrong to me. Take send_photo as an example.

url = '{0}/sendPhoto'.format(self.base_url)

data = {'chat_id': chat_id, 'photo': photo}

if caption:
    data['caption'] = caption

return self._message_wrapper(
    url,
    data,
    chat_id=chat_id,
    photo=photo,
    caption=caption,
    disable_notification=disable_notification,
    reply_to_message_id=reply_to_message_id,
    reply_markup=reply_markup,
    timeout=timeout,
    **kwargs)

To me it seems like at least chat_id, photo, and caption are totally redundant to have as kwargs too, given they are part of the data already.

I propose we figure either use the decorator everywhere (best and cleanest solution in my head) or we scrap it and use the _message_wrapper everywhere (and figure out if we really need all those extra kwargs).