Explicitly include stdint header as the logic uses INT64_MAX, just in case for future, even though the chain of headers from existing includes brings in the definition indirectly as of now.

Cross check for time gap between prngplus reseeding, periodically, has the internal state is being consumed, so that if there is too much time gap, then prng reseeding can be forced, before the normal
reseed window is reached. This is useful for long running programs which trigger dns queries only intermittently.
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