WebExtensions port of Private Tab extension for Firefox/SeaMonkey (see Private_Tab#254).

Issues

Description	Part	Status	Severity	Firefox bug
Ability to create private containers	Core functionality	No API	Block	#47
Ability to manually clear container data (as a temporary replacement for really private tabs)	Core functionality	No API	Block	Bug 1353726
Ability to programmatically enable containers	Core functionality	No API Fixed in Firefox 57+	Major	Bug 1354602
Browser behavior for “open link in new tab” (browser.tabs.insertRelatedAfterCurrent & Co)	UX	No API browser.tabs.create({ openerTabId: … }) in Firefox 57+	Major
Items in bookmark/history context menu	Additional functionality	No API Implemented in Firefox 59+	Minor	Bug 1370499
Ability to update menu item right before menu opening (to implement “Private Tab” checkbox in tab context menu)	UX	No API browser.menus.onShown in Firefox 60+	Minor
Ability to move tab into another container (for “Private Tab” checkbox in tab context menu), to restore not only URL	Additional functionality, UX	No API	Minor
Special private:… protocol to open URIs in private tabs	Additional functionality	No API	Minor	Bug 1271553
Cleanup on disabling/uninstalling: browser.runtime.onSuspend(), browser.runtime.onSuspendCanceled()	Internals + UX	Not implemented Chrome API	Minor
Toolbar button after last tab	UI	No API	Minor
Configurable keyboard shortcuts (note: also not possible to assign Ctrl+Alt+X)	UX	No API browser.commands.update() in Firefox 60+	Minor	Bug 1421811, bug 1303384