Remove alternatives for hash().
Remove alternatives for hash().

This makes the code quite a bit more straightforward and hash() is part of PHP core since 5.1.2 and we require 5.2 as a minimum.

simplesamlphp/xmlseclibs,robrichards/xmlseclibs,tmilos/xmlseclibs,RichWeber/xmlseclibs,hiddewie/xmlseclibs