Convergence

<ul style="text-align: justify;"> <li> Deprecate gnome-session and use upstart/systemd as the root process </li> <li> Deprecate gnome-screensaver (following upstream) and unify screensaver management into the shell </li> <li> Deprecate policykit-gnome and use the shell for PolicyKit handling in both Unity 7 and Unity 8 </li> <li> Deprecate unity-settings-daemon by decoupling the plugins and migrating to new services </li> <li> Add more desktop capabilities in Ubuntu System Settings to replace unity-control-center </li> <li> Enhance the core apps to replace current defaults e.