title: Find binary's in $PATH
body: <p>I am looking for a function to find a binary in all folders which are available in $PATH.<br>
  I know i can use os.Getenv("PATH") but it returns:</p>
  
  <pre><code>path: /usr/local/bin:/usr/bin:/bin:/usr/local/games:/usr/games:/usr/local/go/bin
  </code></pre>
  
  <p>Which needs to be processed.<br>
  Ideally function like this: FindBinary("ntpq") and it will return the path + binary name and false when not found in path.<br>
  Does anybody have a ready function?</p>