non-repeating ID generation
functions provide a facility to generate a stream of 32-bit numbers that are
strongly unpredictable and have a repetition cycle close to 2^32. Such
numbers are useful as protocol identifiers where there are negative
consequences to reusing an ID within a short time period, as may happen if
they are simply assigned at random.
function prepares a context structure for use.
function returns a new ID in host byte order. Note that this function will
never return 0 as it often has a special meaning in network protocols.
idgen32 functions were added in