[all] use explicit void parameter lists

This makes it a compile-time error to call a function that semantically
takes no parameters with a nonzero number of arguments.

Previously, such code would still compile, but risk blowing up the stack
if a compiler chose to use something other than caller-cleanup calling
conventions.

host/platform/Windows/src/mousehook.c

@@ -47,7 +47,7 @@ void mouseHook_install(MouseHookFn callback)
   sendAppMessage(WM_CALL_FUNCTION, 0, (LPARAM)&cf);
 }
 
-void mouseHook_remove()
+void mouseHook_remove(void)
 {
   struct MSG_CALL_FUNCTION cf;
   cf.fn     = msg_callback;