unix: fix uv__open_cloexec usage

It returns the fd or the negated errno.
doc: refer to README.md to find out more information about tests

Reason for this change is because 'make test' command does not work.

Signed-off-by: Luka Perkov <luka.perkov@sartura.hr>
process: adjust quote_cmd_arg for empty arguments

adjust quote_cmd_arg so that empty command line
arguments are double quoted instead of skipped
win: minor coding style cleanup
win: open_named_pipe const argument
unix, windows: uv_dlerror const argument
unix, windows: avoid error in uv_fs_event_stop

For consistency with other handle types, if stop is called while the
handle wasn't started yet, it's a no-op.
windows: getnameinfo implementation for #852

Implementation adds new public function uv_getnameinfo
unix: getnameinfo empty implementation for #852

Skeleton code for uv_getnameinfo fixing unix build
windows: getnameinfo implementation for #852

Renamed var addresssize to address_len and portsize to port_len.
Removed ALIGNED_SIZE usage and moved declaration of struct sockaddr_in.
windows: getnameinfo implementation for #852

Cleanup avoid malloc for host and service.