Fixes

- Removed void* arithmetic
- Fixed connection_send does not return anything
- Fixed server_events invalid args in main.c (and changed its
  declaration)

server.h

@@ -30,7 +30,7 @@ void server_close();
 //    it with connection.h
 //  - you should stop close the server if this function
 //    returns false
-bool server_event(uint32_t events);
+bool server_event(int fd, uint32_t events);
 
 
 #endif