fix mixing up of SDL and libc allocators, proper flushing of quad build buffers

apps/demos/platformer/game.c

@@ -12,7 +12,7 @@
 void game_tick(void) {
     if (ctx.initialization_needed) {
         if (!ctx.udata) {
-            ctx.udata = ccalloc(1, sizeof (State));
+            ctx.udata = calloc(1, sizeof (State));
 
             State *state = ctx.udata;
             state->ctx = &ctx;