- Bumps HOS version from 12.1.0 to 20.0.1.
- Updates the corresponding `VERSION_HASH`, `DISPLAY_VERSION`, and
`DISPLAY_TITLE` strings.
- Updates the copyright year and project name.
Signed-off-by: Zephyron <zephyron@citron-emu.org>
This formats all copyright comments according to SPDX formatting guidelines.
Additionally, this resolves the remaining GPLv2 only licensed files by relicensing them to GPLv2.0-or-later.