code: public static String unescapeTag(String escapedTag)
      {
          // Check that the escaped tag does not contain reserved characters
          checkEscaped(escapedTag, Tag.reservedChars, false);
          // Unescape the tag
          return unescape(escapedTag, Tag.reservedChars);
      }
docs: Unescapes the given escaped tag following RFC 2608, 5.0.
  For example, the escaped tag string <code>file\5fpath</code> will be converted into
  <code>file_path</code>.
  
  @param escapedTag the tag string to unescape
  @return the unescaped tag
  @throws ServiceLocationException if the escaping is wrong
  @see #escapeTag(String)