- Fix (regression): Extension locale loading for non-English locales

- Fix: Allow language to be properly set back to a different locale and
  retaining preference (and ensure language changes are available before
  dialog closed)
- Refactoring: array extra/spread operator
- npm: Update devDep (sinon-test)

package-lock.json

@@ -8996,9 +8996,9 @@
       }
     },
     "sinon-test": {
-      "version": "2.3.0",
-      "resolved": "https://registry.npmjs.org/sinon-test/-/sinon-test-2.3.0.tgz",
-      "integrity": "sha512-dhy6lbkZAvVW6XVsngX9HY0MNBurNPP3vqVdXGYAN4B3BNq3eXO6d5V1nuS7UsjX2tXSk7QhMEb6cUk/Fia95g==",
+      "version": "2.4.0",
+      "resolved": "https://registry.npmjs.org/sinon-test/-/sinon-test-2.4.0.tgz",
+      "integrity": "sha512-oQnO02I7JDbtrSKN8Qs3upobCQRythJCBn3DzPmv4m/SoPvhZJDVqHDFkRZ1lZhN2GkBqOR3m7WT79190z9kEg==",
       "dev": true
     },
     "slash": {
@@ -9934,7 +9934,7 @@
     },
     "text-encoding": {
       "version": "0.6.4",
-      "resolved": "http://registry.npmjs.org/text-encoding/-/text-encoding-0.6.4.tgz",
+      "resolved": "https://registry.npmjs.org/text-encoding/-/text-encoding-0.6.4.tgz",
       "integrity": "sha1-45mpgiV6J22uQou5KEXLcb3CbRk=",
       "dev": true
     },