title: boost::filesystem::file_size error when using a path with whitespace
body: <p>I'm asking <code>boost::filesystem::file_size</code> for a file with path <code>"/tmp/test\ file.txt"</code>, and it reports no such file or directory when it is there.</p>
  
  <pre><code>Error: fs::file_size("/tmp/test\ file.txt") reported boost::filesystem::file_size: No such file or directory
  -rw-rw-r-- 1 rturrado users 12486 Mar 15 12:01 /tmp/test file.txt
  </code></pre>
  
  <p>Are there any considerations when using paths with escaped sequences in boost::filesystem?</p>