added PRF functionality
added PRF functionality

SEED from os.random, now can use HMAC_DRBG PRF function to generate a pseudorandom output to reduce key sizes
theQRL/QRL,randomshinichi/QRL,cyyber/QRL,cyyber/QRL,elliottdehn/QRL,elliottdehn/QRL,elliottdehn/QRL,jleni/QRL,theQRL/QRL,elliottdehn/QRL,jleni/QRL,randomshinichi/QRL