Windows Service support.

Program can now be started as a Windows Service. No additional
arguments needed. Refer to `service_install` and `service_remove`
scripts in released zip file.

goodbyedpi.h

@@ -5,3 +5,6 @@
 #else
 #define debug(...) printf(__VA_ARGS__)
 #endif
+
+int main(int argc, char *argv[]);
+void deinit_all();