Ask user to post as blog if post is too long

[KyleMaas]

Now that we support displaying blog-type posts, it would be nice if we offered the user the choice to post as a blog message if their message is too long for a regular post. Right now we just error out. If we replaced that with something that asks them "This post is too long. You can either return to your post and edit it or post it as a blog post, the downside being that not all clients support viewing them. What would you like to do?" or something to that effect, that might be a better way to handle it.