Infocatcher/Right_Links_WE: WebExtensions port of Right Links extension for Fi...

WebExtensions port of Right Links extension for Firefox/SeaMonkey (see Right_Links#31).

Issues

Description	Part	Status	Severity	Firefox bug
~~Browser behavior for “open link in new tab” (browser.tabs.insertRelatedAfterCurrent & Co)~~	UX	~~No API~~ browser.tabs.create({ openerTabId: … }) in Firefox 57+	~~Major~~
Ability to handle clicks on bookmarks and history items	Core functionality	No API	Major
Ability to handle clicks on internal restricted pages (about:…, chrome://…, especially on about:newtab)	Core functionality	No API	Major
Ability to handle clicks on restricted webpages (like addons.mozilla.org)	Core functionality	May be configured (at your own risk) in about:config: privacy.resistFingerprinting.block_mozAddonManager = true extensions.webextensions.restrictedDomains = "" (empty string, or remove some domains as you like)	Major
Ability to simulate click on JavaScript-links (e.g. with `window.open()` inside)	Core functionality	No API, new tabs/windows will be blocked	Major
Ability to programmatically open context menu	UX	No API	Major
Ability to send HTTP referer	Core functionality	No API	Major
~~Support for canvas images (ability to open data:… and blob:… URIs)~~	~~Core functionality~~	~~Forbidden~~ Works from background script: URL.createObjectURL(Blob)	~~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