title: Escaping filename spaces with singularity %files directive
body: <p>I have a file with spaces in its name that I want to copy to my container:</p>
  <pre><code>%files
     /tmp/some file with spaces /usr/local/bin
  </code></pre>
  <p>I have tried using 1 or 2 backslashes paired with single or double quotes, but the full filename is not recognized.  While I can change the filename, I was curious if there is a way to correctly escape the filename?</p>