A binary package built with xbps is a normal tar(1) archive, compressed
with gzip, bzip2 or lzma and has the following structure:

	/
	/usr ------|
	/var ------| => Package structure that will be installed.
	/etc ------|
	...
	/xbps-metadata
	/xbps-metadata/flist
	/xbps-metadata/props.plist
	/xbps-metadata/postpre-action.sh

The xbps-metadata directory contains all the metadata related to this
package. The flist file contains the list of files that the package will
install. The props.plist file is a proplib(3) property list and
has the following structure:

<dict>
	<key>architecture</key>
	<string>x86_64</string>
	<key>installed_size</key>
	<integer>500000</integer>
	<key>configuration_files</key>
	<array>
		<string>/etc/foo.conf</string>
		...
	</array>
	<key>run_depends</key>
	<array>
		<string>bofh-2.0</string>
		<string>foof-1.1</string>
		...
	</array>
</dict>

This plist might be extended in the future if it's required or useful.

The postpre-action.sh script will be run as specified in the script,
and will do post/pre installation steps required for this package.