[ADF-1115] selection management for DT/DL components (#2100)

* row select/unselect dom events for DT

- new events for datatable
- improved unit tests for empty content placeholders

* improved selection management for DT

* selection management for document list

* fix tests

ng2-components/ng2-alfresco-datatable/src/components/datatable/datatable.component.html

@@ -55,7 +55,10 @@
             </td>
 
             <td *ngIf="multiselect">
-                <md-checkbox [(ngModel)]="row.isSelected"></md-checkbox>
+                <md-checkbox
+                    [checked]="row.isSelected"
+                    (change)="onCheckboxChange(row, $event)">
+                </md-checkbox>
             </td>
             <td *ngFor="let col of data.getColumns()"
                 class="adf-data-table-cell adf-data-table-cell--{{col.type || 'text'}} {{col.cssClass}}"