Add uv_device_t as stream on windows and linux, handle device I/O asyn
Update stream.c

fix whitespace
remove unusable variable and not need code.
change uv_device_t mainly, according to @saghul guide.
update uv.gyp for support uv_device_t
add test of uv_device_t, by tun or tap-windows tap
revert change thant not related to uv_device_t
update test-device-tun-echo.c
update Makefile.am (fix style)
update alloc_cb use libuv pattern
keep parameter style same with libuv
update (whitespace) style
change uv_ioargs_t to *nix style