fix(datepicker): for issue #1962 (#1991)

fixes #1962
Now activeDateChange event get fired then the date changed, before the event only gets fired then you use the arrows (back and forward buttons) in top of the calendar.

src/datepicker/datepicker-inner.component.ts

@@ -105,6 +105,17 @@ export class DatePickerInnerComponent implements OnInit, OnChanges {
   // tslint:disable-next-line:no-unused-variable
   public ngOnChanges(changes: SimpleChanges): void {
     this.refreshView();
+    this.checkIfActiveDateGotUpdated(changes.activeDate);
+  }
+
+  //Check if activeDate has been update and then emit the activeDateChange with the new date
+  private checkIfActiveDateGotUpdated(activeDate: any): void {
+		if (activeDate && !activeDate.firstChange) {
+			let previousValue = activeDate.previousValue;
+			if (previousValue && previousValue.getTime() !== activeDate.currentValue.getTime()) {
+				this.activeDateChange.emit(this.activeDate);
+			}
+		} 
   }
 
   public setCompareHandler(handler: Function, type: string): void {
@@ -219,9 +230,6 @@ export class DatePickerInnerComponent implements OnInit, OnChanges {
       }
 
       this.activeDate = new Date(date.getFullYear(), date.getMonth(), date.getDate());
-      if (isManual) {
-        this.selectionDone.emit(this.activeDate);
-      }
     } else {
       this.activeDate = new Date(date.getFullYear(), date.getMonth(), date.getDate());
       this.datepickerMode = this.modes[this.modes.indexOf(this.datepickerMode) - 1];