Bug 1441617 - Switch the userguide module to ES6 exports

And whilst we're there, use explicit imports instead of relying on
the webpack `ProvidePlugin` to import it for us - which lets us also
remove the eslint global exemption plus unit test workaround.

neutrino-custom/base.js

@@ -256,7 +256,6 @@ module.exports = neutrino => {
             treeherderApp: require.resolve(path.join(UI, 'js/treeherder_app.js')),
             perf: require.resolve(path.join(UI, 'js/perf.js')),
             logViewerApp: require.resolve(path.join(UI, 'js/logviewer.js')),
-            userguideApp: require.resolve(path.join(UI, 'js/userguide.js'))
         });
 
     neutrino.config.devtool('source-map');

neutrino-custom/lint.js

@@ -91,7 +91,6 @@ module.exports = neutrino => {
                     'SERVICE_DOMAIN',
                     'treeherder',
                     'treeherderApp',
-                    'userguideApp',
                 ]
             }
         }));

tests/ui/unit/init.js

@@ -30,7 +30,6 @@ window.treeherder = jsContext('./treeherder.js');
 window.treeherderApp = jsContext('./treeherder_app.js');
 window.perf = jsContext('./perf.js');
 window.logViewerApp = jsContext('./logviewer.js');
-window.userguideApp = jsContext('./userguide.js');
 window.SERVICE_DOMAIN = process.env.SERVICE_DOMAIN || '';
 jsContext('./values.js');
 jsContext('./providers.js');

ui/entry-userguide.js

@@ -8,6 +8,8 @@ require('./css/treeherder-userguide.css');
 require('./css/treeherder-job-buttons.css');
 require('font-awesome/css/font-awesome.css');
 
-// Userguide JS
+// Bootstrap the Angular modules against which everything will be registered
 require('./js/userguide.js');
+
+// Userguide JS
 require('./js/controllers/userguide.js');

ui/js/controllers/userguide.js

@@ -1,3 +1,5 @@
+import userguideApp from '../userguide';
+
 userguideApp.controller('UserguideCtrl', ['$scope',
     function UserguideCtrl($scope) {
 

ui/js/userguide.js

@@ -1,4 +1,4 @@
-var userguideApp = angular.module('userguide', []);
+const userguideApp = angular.module('userguide', []);
 
 userguideApp.config(['$compileProvider', function ($compileProvider) {
     // Disable debug data, as recommended by https://docs.angularjs.org/guide/production
@@ -12,4 +12,4 @@ userguideApp.config(['$compileProvider', function ($compileProvider) {
     );
 }]);
 
-module.exports = userguideApp;
+export default userguideApp;