Feature: printf

[KieranP]

https://en.wikipedia.org/wiki/Printf

example c++:

printf(
  "#%d - World Tick (L: %.3f; A: %.3f) - Rendering (L: %.3f; A: %.3f)\n",
  world->tick,
   _f(lowest_tick),
  _f(avg_tick),
  _f(lowest_render),
  _f(avg_render)
);