(you can change the name of the file from defaults.php);
as salt is based on the path on the server, if you had to move to another directory or to another server, then you wouldn't be able to login anymore and you had to reinstall, now this shouldn't be needed anymore; moreover as this is now safe in a file we can add additional security by
* concatenating the default paths+random blog id to another random number, which is not written anywhere else
* changing the contents with your very own salt string: then re-run setup and overwrite your old user: the hashsalt won't be overwritten (this needs testing)
