function unescape(key) {
	  var unescapeRegex = /(=0|=2)/g;
	  var unescaperLookup = {
	    '=0': '=',
	    '=2': ':'
	  };
	  var keySubstring = key[0] === '.' && key[1] === '$' ? key.substring(2) : key.substring(1);

	  return ('' + keySubstring).replace(unescapeRegex, function (match) {
	    return unescaperLookup[match];
	  });
	}
Unescape and unwrap key for human-readable display

@param {string} key to unescape.
@return {string} the unescaped key.