Calendar onMonthChange is not triggered when change monthNavigator

[raymond-kolorbox]

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Plunkr Case (Bug Reports)
http://plnkr.co/edit/NNI7d6vSzy7xsljo5zVr?p=preview

Current behavior
Calendar onMonthChange is not triggered when change in yearNavigator or monthNavigator

Expected behavior
onMonthChange should be triggered when change in yearNavigator or monthNavigator

Minimal reproduction of the problem with instructions
<p-calendar [(ngModel)]="selected_date" [inline]="true" [monthNavigator]="true" [yearNavigator]="true" yearRange="2015:2050" dateFormat="yy-mm-dd" (onMonthChange)="changeMonth($event)">
Set onMonthChange Handler to p-calendar, change month in monthNavigator or year in yearNavigator do not trigger the onMonthChange Handler.

What is the motivation / use case for changing the behavior?
Update in monthNavigator and yearNavigator to get events in new month.

Please tell us about your environment:
MacOS Sierra, Visual Studio Code, npm, yarn, nginx

• Angular version: 2.0.X
  5.0.1

• PrimeNG version: 2.0.X
  5.0.2

• Browser: [all | Chrome XX | Firefox XX | IE XX | Safari XX | Mobile Chrome XX | Android X.X Web Browser | iOS XX Safari | iOS XX UIWebView | iOS XX WKWebView ]
  all

• Language: [all | TypeScript X.X | ES6/7 | ES5]
  all

• Node (for AoT issues): node --version =
  6.10.3