PackageSorter weighs the importance of a package
by counting how many times it is required by other packages.
This works by calculating the weight for each package name.
However currently the package index of the package array
is currently passed the weigh function, which basically
disables package sorting.
The reason for that is, that a package repository previously
returned the package list as associative array with package name as keys,
but currently just as an array with integer keys.
Therefore we must extract the package name from the package
before passing it to the weigh function.
Jordi Boggiano