sketch out os api, binary stream writer in js, app sleep when no animation, local and universal time

src/os/os_unix.c

@@ -1,4 +1,4 @@
-fn os_date_t os_date_now(void) {
+fn os_date_t os_local_time_now(void) {
     os_date_t result = {0};
     time_t time = time(NULL);
     struct tm *lt = localtime(&time);