SPDX standardizes how source code conveys its copyright and licensing
information. See https://spdx.github.io/spdx-spec/1-rationale/ . SPDX
tags are adopted in many large projects, including things like the Linux
kernel.
The difference between Dolphin's game IDs and GameTDB's game IDs
is that GameTDB uses four characters for non-disc titles, whereas
Dolphin uses six characters for all titles.
This fixes:
- TitleDatabase considering Datel discs to be NHL Hitz 2002
- Gecko code downloading not working for discs with IDs starting with P
- Cover downloading mixing up discs with channels (e.g. Mario Kart Wii
and Mario Kart Channel) and making extra HTTP requests. (Android was
actually doing a better job at this than DolphinQt!)
