i18n fixes (#1614)

* i18n fixes

- fix issue with default (fallback) language set to browser language
- fix issue with fallback language loading when browser language set to
non-English locale

* code and UI fixes

- move document list i18n strings into own scope
- replace MDL menu with @angular/material menu (fixes issue with menu
items translation, not supported by MDL)
- minor improvements

* fix unit tests

* improve i18n docs and code

- provide basic documentation for Translation service
- remove custom Login component localisation in favour of documentation
sample
- simplified i18n setup for demo shell (single path for dev/prod env)

* remove unnecessary comments

demo-shell-ng2/app/app.component.ts

@@ -43,13 +43,7 @@ export class AppComponent {
         this.setProvider();
 
         if (translateService) {
-            if (process.env.ENV === 'production') {
-                translateService.addTranslationFolder('custom', 'i18n/custom-translation');
-                translateService.addTranslationFolder('ng2-alfresco-login', 'i18n/custom-translation/alfresco-login');
-            } else {
-                translateService.addTranslationFolder('custom', 'custom-translation');
-                translateService.addTranslationFolder('ng2-alfresco-login', 'custom-translation/alfresco-login');
-            }
+            translateService.addTranslationFolder('app', 'resources');
         }
     }
 
@@ -75,7 +69,7 @@ export class AppComponent {
             );
     }
 
-    navigateToLogin(){
+    navigateToLogin() {
         this.router.navigate(['/login']);
         this.hideDrawer();
     }