The docking has been removed yes. It wasn't an actual dock it just snapped the window to the side. A real docking window will change the usable screen area which Plus! never did. There was a plugin called Windows Management Plugin that did similar things as this. I haven't heard if Taz is working on it or not.
i am just stuck in finding a good name for the plugin/script for all the new functionality
ok, i am not stuck but on the lookout.
slowly adding back, some functionalities
Argg i really need to re-design the preferences window to match everything else
Window Manager is discontinued, for WLM try the new, Enhancer for contact list docking, auto-hide, hide taskbar button, remove button flashing and remember keyboard layout in conversation windows