WebExtension Tab for Firefox 57 (#469)
WebExtension Tab for Firefox 57 (#469)

* Refactor tabs.Tab data

* Refactor tabs.query data

* Note support for queryData.discarded in Firefox 57

* Refactor tabs.create data

* Note support for openerTabId in Firefox 57 (desktop only)

* Note that Firefoxes < 57 couldn't open view-source:

teoli2003/browser-compat-data,mdn/browser-compat-data,chrisdavidmills/browser-compat-data,chrisdavidmills/browser-compat-data,mdn/browser-compat-data