fixes #587 by making uniqe ids more unique

For environments like mentioned in the docs:
http://www.php.net/manual/en/function.uniqid.php#refsect1-function.uniqid-notes
> Under Cygwin, the more_entropy must be set to TRUE for this function to work.
this method will just return the same result if called again in the same mikrosecond
Merge pull request #594 from karfau/patch-1

fixes #587 by making uniqe ids more unique