allow kvm options to be passed on for test target
allow non-resolvable links specified as init= command
prepare_file: use optional second arg as save destination
let prepare_file to use "*" wildcard, copy to dst not done by lower lvl
implement :xxxx filename (last dev reuse) logic for prepare_file
unmount temporary mounts during finalize
helper functions for incremental aufs building
add experimental copy-up http remote filesytem support