by using our DeflateEncoder
for this to work, we have to create wrapper reader that generates the crc32
checksum while reading.
also we need to put the target writer in an Option, so that we can take
it out of self and move it into the DeflateEncoder while writing
compressed
we can drop the internal buffer then, since that is managed by the
deflate encoder now
Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>
d84e4073af