make binary module or (better) add support for abstract cockets to libuv about abstractsocket HOT 2 OPEN

Prior art:
python:
https://docs.python.org/3/library/socket.html#socket-families
http://blog.eduardofleury.com/archives/2007/09/13

ruby:
http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-core/11322?help-en
https://bugs.ruby-lang.org/issues/7786

from abstractsocket.

abstract sockets + supported by uv! joyent/libuv@5ac214c

what needs to be added at src/unix/pipe.c:uv_pipe_connect :

1. uv_pipe_connect - add name_length paramer
2. replace strncpy with memcpy as strncpy stops at first "\0"
3. instead of using sizeof saddr need to use size up to last character in saddr.sun_path
   for example, for "\0/tmp/dbus123" address call needs be connect(uv__stream_fd(handle), (struct sockaddr*)&saddr, 15);

from abstractsocket.