md-text-float doesn't forward ng-change function

[rosterloh]

Is it possible to add the ng-change functionality to the md-text-float component?
Currently

<md-text-float label="Days" ng-model="home.time.durationD" ng-change="home.timeChange()"> </md-text-float>

does not call the function but

<md-input-group tabindex="-1">
    <label for="days" >Days</label>
    <md-input id="days" ng-model="home.time.durationD" type="text" ng-change="home.timeChange()"></md-input>
</md-input-group>

does

[Frank3K]

Related: #547.