Done ATTRIB enhancements

Charles Dye wrote:
| Any chance of ATTRIB supporting +C -C +E -E to set/clear the
| Encrypted and Compressed attributes in v11?

AFAIK they are not plain attributes as ASHR are, to change them would
require to change the file bodies. Separate command(s) might be more
suitable for the purpose. However, I agree they would be desirable.