Don't use global IPADDRESSES in addr_lib

This is in preparation for move of IPADDRESSES to EvalContext.
Don't use IPADDRESSES in cf-execd-runner subprocess

Instead pre-calculate ip addresses header in parent and pass
it in ExecConfig struct to a child.

This is in preparation for moving of IPADDRESSES to EvalContext.
Move IPADDRESSES to the EvalContext struct

This also makes memory management for this list simpler.