title: NLog auto truncate messages
body: <p>I'm logging my messages to a database field with a max size of 1000 characters. Currently if I try to log a message (which often contains exception information with stack trace, HTTP request content, etc.) that's larger than 1000 characters, the insert fails and NLog (as it should) silently ignores that and keeps going.</p>
  
  <p>Is there something I can put in my NLog.config to declare that the message length should always be truncated so it's no greater than 1000 characters?</p>
  
  <p>Bonus points if you can tell me how to gracefully mark truncated messages by replacing the last few characters before the 1000 character limit with something like <em>"[...Truncated]"</em>.</p>
  
  <p>Can't believe I can't readily find this with some googling. Hopefully I don't have to write my own renderer?</p>