Compiler warning cleanup
- gitlab CI: stop requiring
Signed-off-byin commits - constify some argument declarations
- S3VSetupImageVideoOverlay: Fix 44
-Wnull-dereferencewarnings from gcc - S3VSetCursorColors: quiet
-Wimplicit-fallthroughwarnings
Signed-off-by in commits-Wnull-dereference warnings from gcc-Wimplicit-fallthrough warnings