Fixes

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

server.c

@@ -91,7 +91,7 @@ void server_close() {
     close(_fd);
 }
 
-bool server_event(uint32_t events) {
+bool server_event(int fd, uint32_t events) {
     if (events & EPOLLIN) {
         return _accept();
     }