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.
unix, windows: getnameinfo implementation

Closes #852
heap: fix `heap_remove()`

Remove should shuffle items in both directions, not just down. It is
required, because `max` node could be not the actual maximum value in
the tree.

fix #1267

Signed-off-by: Fedor Indutny <fedor@indutny.com>
windows: remove redundant code in uv_tcp_write

The overlapped structure is reset twice, it is non necessary.

Signed-off-by: Fedor Indutny <fedor@indutny.com>
unix, windows: define UV__INET/6_ADDRSTRLEN constants
unix, windows: fix parsing scoped IPv6 addresses

Signed-off-by: Saúl Ibarra Corretgé <saghul@gmail.com>
doc: clarify return value when UV_RUN_NOWAIT is used

Signed-off-by: Saúl Ibarra Corretgé <saghul@gmail.com>
windows: fix handling closed socket while poll handle is closing

fixes #1278
windows: required environment variables

adds more of the undocumented-but-required environment variables for uv_spawn