not guaranteed to be signed, so comparison with -1 will cause a
warning (turned error) for some of our ports (e.g. our arm ports).
Fix this by making the 'ch' variable an int instead of a char.
images from "normal" into cloop2-format compressed images and back.
Written by Florian Stoehr (netbsd@wolfnode.de) with some polishing
by me.
Compressed disk images can be used with the vnd(4) driver when compiled with
VND_COMPRESSION and "vnconfig -z". Useful for creation of Live CDs/DVDs.
