version requirements for Socket import inet_pton
Adding new_ipv4_cidr and correcting a bug

because pos is a position and substr is looking for a length, doing
"pos-1" was incorrect.  pos+1 for the cidr portion was correct because
the second argument (offset) is a position that starts from zero.
updating testing to add test for new_ipv4_cidr
splitting benchmarks

Just makes it easier for me to run them depending on what I'm testing
new_ipv4_cidr now uses a lookup table