changelog:
- fixed "Popup All Tabs" command not working
- added "Tab Position" option for "Open Link In New Tab"
- changed "Open Link In New Tab" will now follow the normal browsing behaviour (specified in the about:config - browser.tabs.insertRelatedAfterCurrent and browser.tabs.insertAfterCurrent) on default
- added "Tab Position" options "start" and "end" for all related commands