Mail-Ngrx app throws errors for certain rxjs operators

+ Various other small code fixes

src/app/main/content/apps/calendar/calendar.component.ts

@@ -25,21 +25,13 @@ import { fuseAnimations } from '../../../../core/animations';
 export class FuseCalendarComponent implements OnInit
 {
     view: string;
-
     viewDate: Date;
-
     events: CalendarEvent[];
-
     public actions: CalendarEventAction[];
-
     activeDayIsOpen: boolean;
-
     refresh: Subject<any> = new Subject();
-
     dialogRef: any;
-
     confirmDialogRef: MatDialogRef<FuseConfirmDialogComponent>;
-
     selectedDay: any;
 
     constructor(

src/app/main/content/apps/mail-ngrx/mail.component.ts

@@ -7,6 +7,8 @@ import { locale as english } from './i18n/en';
 import { locale as turkish } from './i18n/tr';
 import { Store } from '@ngrx/store';
 import { Observable } from 'rxjs/Observable';
+import 'rxjs/add/operator/debounceTime';
+import 'rxjs/add/operator/distinctUntilChanged';
 import * as fromStore from './store';
 import { FuseConfigService } from '../../../../core/services/config.service';
 

src/app/main/content/apps/mail-ngrx/store/effects/mails.effects.ts

@@ -4,6 +4,7 @@ import { Actions, Effect } from '@ngrx/effects';
 import { Observable } from 'rxjs/Observable';
 import { of } from 'rxjs/observable/of';
 import { map, mergeMap, exhaustMap, withLatestFrom } from 'rxjs/operators';
+import 'rxjs/add/operator/debounceTime';
 import { getRouterState, State } from '../../../../../../store/reducers';
 import { getMailsState } from '../selectors';
 import * as MailsActions from '../actions/mails.actions';

src/app/main/content/apps/todo/todo-list/todo-list-item/todo-list-item.component.scss

@@ -10,13 +10,6 @@
     flex-shrink: 0;
     background: #FFFFFF;
 
-    &.todo-item-placeholder {
-        background: rgba(0, 0, 0, 0.12);
-        * {
-            opacity: 0;
-        }
-    }
-
     .handle {
         height: 48px;
         line-height: 48px;