Fix HTTPS functionality on _WIN32
- libwget/ssl_gnutls.c: Add _win32_send() and _win32_recv(), set those functions as push and pull functions on _WIN32.
Sets the GnuTLS pull and push functions to make gnulib sockets work. Tested only on MinGW64.
Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
Sets the GnuTLS pull and push functions to make gnulib sockets work. Tested only on MinGW64.