Fix corrupted textual BASIC filetyped as tokenised
- Replace tokenised license header with untokenised version.
- Strip line numbers
- Retype textual BASIC files to BASICTxt, See Programmer's Reference Manual Volume 4 Table C and RiscOS/Sources/FileSys/FileSwitch!9 (merged) for the filetype.
Found whilst testing Support/RepoTools!16 (merged).