Do not (auto-)restart user-session@.service.
Use %I for user-session@.service and start it in parallel with gettys.
Split synaptiks@.service into itself and synaptikscfg@.service.

In my setup, Synaptiks GUI crashes on startup (packaging problems, I
think), so decouple it from the GUI-less touchpad initialization which
works properly and is more critical.
Add a helper unit need-primary-xserver.service (analogous to need-xserver@.service) and use it.
Add an [Install] section to dbus.service.
Fix description of dbus.socket (System -> Session).
Remove an IS_SOLARIZED=1 urxvt hack (handled more-or-less properly in my .bashrc now).
Tweak gpg-agent.service for less errors.
Make Scroll Lock LED useful. (xkb@.service)