This commits adds an "Advanced configuration" option to screen filters,
where CCT, color gamma, contrast and "brightness" can be fine-tuned,
instead of just using a preset.
Persistence in config.ini TBD in a later commit.
- transform some error codes into "NAND damaged" or "Gamecard removed"
like official errdisp does
- fix bug in SetUserString
- add more info to logfile (/luma/errdisp.txt)