Rar format compression and decompression cannot be used

[zjq609177738]

Rar format compression and decompression cannot be used .

[getnamo]

Rar compression cannot be used due to licensing (see https://github.com/getnamo/7zip-cpp/blob/master/LICENSE.txt). Rar decompression however is usable with 7z.dll, but rar isn't available at all if using the slimmer feature set in 7za.dll.