Add automatic query of EGD sockets to RAND_poll(). The EGD sockets are

Add automatic query of EGD sockets to RAND_poll(). The EGD sockets are
only queried when the /dev/[u]random devices did not return enough
entropy. Only the amount of entropy missing to reach the required minimum
is queried, as EGD may be drained.
Queried locations are: /etc/entropy, /var/run/egd-pool