Add new script: puavo-img-clone
puavo-img-clone: add support for squashfs destination
puavo-img-clone: misc refactoring
puavo-img-clone: update the internal image name too
puavo-img-clone: rename variables
puavo-img-clone: handle -t and -s flags
Add new script: puavo-img-chroot
puavo-img-clone: create the tmp dest file into the same dir as the real dest file
puavo-img-clone: use du to estimate the source size
puavo-img-clone: support kKMGT suffixes in --size option
puavo-img-clone: define imgname in global scope
puavo-img-clone: define dstdir in global scope
puavo-img-clone: simplify cleanup by using EXIT trap
puavo-img-clone: rename variable for the sake of uniformity
puavo-img-clone: calculate dstsize in global scope
puavo-img-clone: add --dont-update-name option
puavo-img-clone: use true/false instead of 0/1
puavo-img-clone: warn if --size and --type squashfs is used together