Move Windows port to MinGW

- Add calls to WSAStartup in the network code as required by
  Winsock.
- Add Windows-specific init_random_state function which uses the
  Crypto API.
- Move Windows port to MinGW and update build system to create a
  64-bit binary by default.
- Install text files as .rtf so they won't open in Notepad by default
  (Wordpad understands Unix line endings; Notepad doesn't).
- Simplify WiX installer code.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/client.c b/client.c
index f167549..ace70d3 100644
--- a/client.c
+++ b/client.c
@@ -404,6 +404,11 @@
 	struct flist_head *entry, *tmp;
 	int ret;
 
+#ifdef WIN32
+	WSADATA wsd;
+	WSAStartup(MAKEWORD(2,2), &wsd);
+#endif
+
 	dprint(FD_NET, "client: connect all\n");
 
 	client_signal_handler();