From Andreas:

New class providing package management functionality like the AliEn      
Package Management System.                                           
Allows to setup software packages on a local desktop like in the    
GRID environment and to execute the contained programs.              
Registered Dependencies are automatically resolved and missing       
packages are automatically installed.                                
Currently there is no support for 'source' packages.                 
The desired platform has to be specified in the constructor.         
The default constructor takes packages from the global package       
section in AliEn. If you want to install a user package, you have to 
set the AliEn package directory to your local package directory using
     package->SetAliEnMainPackageDir("/alice/cern.ch/user/..../packages")


git-svn-id: http://root.cern.ch/svn/root/trunk@23863 27541ba8-7e3a-0410-8455-c3a389f83636