title: Can one add custom third-party logging Handler to finagle?
body: <p>I was fairly surprised to discover, there is no (or rather I cannot find?) good way to do it:
  <code>com.twitter.logging.Logging</code> has a nice method <code>handlers</code>, that seems to be intended exactly for this purpose, however, it is supposed to return a <code>List[com.twitter.loggin.Handler]</code>, and this <code>Handler</code> is not even a trait, but an abstract class.</p>
  
  <p>So, if I need to integrate with, for example, <code>SentryHandler</code>, what are my options? The only thing I can think of is to hook into <code>premain</code> and shove my handler into the root logger (no, I am not considering implementing <em>another</em> ProxyHandler). It works, just seems kinda ... wrong? </p>
  
  <p>Am I missing something?</p>