1. Do not modify the map after loading. Instead, return string views
(guaranteed to be null-terminated) from look up functions and return
the key directly if not found.
2. Use an `unorded_map` instead of `map` where available (C++20).
Saves a bit of RAM (~50 KiB) and improves lookup performance.
1. TTF no longer crashes on exit.
2. Art failing to load simply isn't rendered instead of crashing in random places.
3. Fixes empty line rendering in ttf_render_wrapped.cpp
4. dx_cleanup is now idempotent.
Gleb Mazovetskiy
Anders Jenbo
Vladimir Olteanu
BDC