Make the change event triggering configurable

[fpesenti]

Description (required)

This PR makes the triggering of the change event configurable. In the previous versions this event was always triggered and in some cases could be useful to be able to react when the list changes.

Merge checklist (required, for maintainers only)

This pull request adheres to the following requirements:

• [] JavaScript follows 4 space indentation conventions.
• [] JavaScript was written using ES2015 (ES6) features.
• [] Features and bug fixes are covered by test cases.
• [] All commits follow the AngularJS Git Commit Message Conventions.