[entropy.client.package] remove useless del calls
[entropy.client.package] extend the preservedlibs module with more methods
[entropy.client.package] correctly handle symlinks to hardlinks, see Gentoo bug #406837
[entropy.client.package] initial preserved libraries support
[client] add new paths to POTFILES.in
[entropy.client.package] force self._root to unicode
[entropy.client.package] expose a list() method, wrap listAllPreservedLibraries()
[entropy.db] add atom field to preserved_libs metadata