rich-text editor: onTextChange called on initialization when value exist

[tleveque23]

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Plunkr Case (Bug Reports)
http://plnkr.co/edit/UkMtjkcVS2Xz0klZu6Ha?p=preview

Current behavior
When an editor (rich-text) component is initialized, if there is already some text in the model, the onTextChange callback is called.

Expected behavior
It should only be called when the text in the editor actually change.

Minimal reproduction of the problem with instructions
See the plunker. The counter is initialized to 0 but it is incremented right away to 1 on load:
http://plnkr.co/edit/UkMtjkcVS2Xz0klZu6Ha?p=preview

What is the motivation / use case for changing the behavior?
Well, we need to be able to enable a save button only when there is really a change in the editor

Please tell us about your environment:

• Angular version: 5.1.X

• PrimeNG version: 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 =