We now use getaddrinfo syscall instead of parsing /etc/hosts in order to
resolve hostnames

RPC port can now be configured at runtime through `--bind-port` command line argument.

For some comunication layers an out of band communication is required for putting in place the specific protocol handshake.

In those case a shared lookup file could be used to distribute deamon's endpoints information to all the clients.

This file need to resides on a shared filesystem and can be specified using the new CLI parameter `--lookup-file`.

gid and uid metadata fields have never been used and can be removed
safely

The access RPC have been removed. The POSIX access functionality now is implemented through the stat RPC. This makes code easier to maintain and modify.

There would be a little performance degradation on the POSIX access
function because we are now retrieving also the metadata
associated to the file.

This change makes a lot easier to add symlink support