Add skeleton for Factory tests
Skipp "Permission denied" for non-root ICMP socket tests
Test less common creation methods
Fix typo, preventing UDG socket creation
Unify creating Factory instance
Test createClient() and createServer()
Add tests for expected exceptions
Stricter tests for unbound ports
Test UNIX and UDG servers
Add ICMP server and UDP6 client test
Add (failing) test for addressing ICMPv6
Declare test dependencies for UNIX and IPv6 sockets
Merge branch 'tests'
Additional check for null return codes
Fix ICMPv6 addressing