* Made the GC switchable at rutime (once) when compiled with S_USE_GC set. * replaced: * malloc -> s_malloc * free -> s_free * realloc -> s_realloc * calloc -> s_calloc
* Made s_[malloc, calloc, free, realloc] functions and moved them to their own file. This can be used os basis for other memory stuffs in the future, if we want to use a Slab allocator or something else.