happy v0.0

Features:

• uses getaddrinfo(...) to resolve service names to endpoints.
• uses non-blocking connect(...) to connect to all endpoints of a service.
• uses a short delay between connection attempts to avoid SYN floods
• the delay between connection attempts is configurable.
• the service name resolution time is not accounted in the output.
• capability to read the input service names list from a file.
• file locking capability when stdout points to a regular file.
• can produce either human-readable or machine-readable output.
• can sort the output for all endpoints for a service name.

Corner cases:

• connection timeouts have status OK and measured times are on the negative scale.
• small negative timeouts indicate a pending error on the socket, SO_ERROR <> 0.
• status is FAIL when happy runs out of socket descriptors.