code: function _gpfPathRelative (from, to) {
      var length,
          splitFrom = _gpfPathDecompose(from),
          splitTo = _gpfPathDecompose(to);
      _gpfPathShiftIdenticalBeginning(splitFrom, splitTo);
      // For each remaining part in from, unshift .. in to
      length = splitFrom.length;
      while (length--) {
          splitTo.unshift("..");
      }
      return splitTo.join("/");
  }
docs: Solve the relative path from from to to
  
  @param {String} from From path
  @param {String} to To path
  @return {String} Relative path
  @since 0.1.9