title: How to suppress confirmation "Launch '$difftool' [Y/n]:" iff (if and only if) a specific file is passed to git difftool?
body: <p>When merging branches or reviewing all changes against a revision with <code>git difftool</code> it might make sense to ask <code>Launch '$difftool' [Y/n]:</code> before every invokation of the tool in order to make the long chain of invokations interruptible with <code>SIGINT</code>. When a specific file is passed as argument it does not, AFAIK. How to suppress that question only in the latter case (because it makes sense to ask it the former)? </p>
  
  <p>I'm using 2.1.0 on Ubuntu 14.10.</p>
  
  <p><strong>EDIT</strong>: After seeing <a href="https://stackoverflow.com/questions/7897517/why-git-difftool-does-not-open-the-tool-automatically">Why does &quot;git difftool&quot; not open the tool directly?</a> I modify the question in order to figure out how to deal with the fact that it makes sense to ask if there's more than one file to diff.</p>