Firefox extension adding link context menu item to launch in a new window in the same container as the current tab
UNFINISHED
See: https://old.reddit.com/r/firefox/comments/1at1aie/is_there_a_way_to_open_a_popup_container/
jscher2000/same-container-popup
Firefox extension adding link context menu item to launch in a new window in the same container as the current tab
JavaScriptMPL-2.0