Features
--------

binary installs

package metadata

package integrity
	gpg signatures
	sha256 sums
	sha3 sums

package contents integrity
	sha256 sums of installed files
	sha3 sums
	sha1 sums
	lists of directory contents

package database editing
	e.g. marking a file as a configuration file

repackaging
	creating a package from the current state of an installed package

package a tarball
	create a package from a tarball

package from stdin
	like cpio

package a directory
	like tar

build from shell scripts

rebuild a package

write ahead log for package filesystem operations
	it should always be possible for the package system
	to figure out if it was interrupted

install, uninstall, upgrade, and downgrade hooks

dependency tracking

network fetching of packages and package databases
reference counting of dynamic libs

simple packaging constructs
	use shell scripts where possible
	use shell functions as hooks and callbacks

package is just a tarball
can contain more than one package
xz compressed

version?
package-name/version/files/{usr/bin/foo, etc}
package-name/version/info/hooks - shell script of functions
package-name/version/info/pkginfo - shell readable
package-name/version/info/manifest? derivable from tarball
package-name/version/info/dynamiclibs, or greppable from manifest?

/var/lib/zpac:
packages/installed/<package>/files/sha1/ab/ab/hash -> file
librefs/<library name>/<package> (or file?)
sha1/ab/ab/<sha1hashs> -> file
fileowner/sha1/ab/ab/hash/packagename - can be more than one

need to mark a package as held for no automatic upgrade

configure to run a command after an any package work