Mostly just cleanup and renaming of certain stuff (mostly in dependencies).
* Changed uw and sw to usize and ssize.
* Removed zpl_cast usage throughout dependencies
* No longer using GEN_DEF_INLINE & GEN_IMPL_INLINE
* header_start.hpp renamed to platform.hpp for depdendencies header.
I need to manually review these as the changes have various errors that are difficult to diagnose why.
I took a break to do handmade hero and now a bit rusty.