Debian bug 677275 - random() max value

	* libmisc/salt.c: random() max value is 2^31-1 (same as RAND_MAX
	on GNU). As it is not clear whether on some systems the max value
	can exceed this number and whether some systems have max values
	which would be lower, we take this into account when defining the
	salt size and number of rounds for SHA encrypted passwords. Higher
	values are favored.