Missing functions in glib-sys

[antoyo]

Hello. The following function is missing in glib-sys: g_io_channel_win32_new_socket () I think there's also some other win32-related functions that are missing. Thanks to add them (ideally with a #[cfg(windows)] attribute).

[EPashkin]

First problem that it not present in your GLib-2.0.gir and we don't will to add patches to it. glib-sys also contains only one file and there no place to add manual part to it. For second, If I remember right: long ago we decide that files and other system-related operation better handled by rust code and we minimize implementation glib part for it.