Re: Where is xfce4-taskbar-plugin?
Sorry for intruding but I don't understand this topic.
The link you posted clearly states that the plugin is now part of xfce4-panel. It most likely corresponds to the Window buttons panel item, which provides the classic taskbar. By the way, 4.10 > 4.4. Don't ask
The "Stick" menu item makes a window sticky i.e. always present on the current workspace. It does not turn your taskbar into a dock. It was renamed "Always on visible workspace" for a good reason, "Stick" is clearly too cryptic.
husband@wife$ make sandwich
husband@wife$ sudo make sandwich