* fix: free-before-init in renwin_init_surface when using sdl renderer
`ren->rensurface.surface` presupposes zero-initialized rensurface.
Rensurface was not actually zero-initialized.
It is now.
* fix: heap buffer overflow in process_env_free
`process_env_free` presupposed that it was null-terminated.
Pass length to free instead.
* use calloc instead of memset for zero-init
Co-authored-by: Guldoman <giulio.lettieri@gmail.com>
---------
Co-authored-by: Guldoman <giulio.lettieri@gmail.com>
