Make null values inherently htmlSafe

[Frozenfire92]

If I don't have a property set on a controller yet (could be set on an init function or similar) then you will get the deprecation notice for binding style attributes

Example

someInit: function(){
  this.set('myProp', Ember.String.htmlSafe('width: 50%;');
}

<div style={{myProp}}>...</div>

To fix this you must explicitly do the following (which seems a little overkill)

myProp: Ember.String.htmlSafe(""),
someInit: function(){
  this.set('myProp', Ember.String.htmlSafe('width: 50%;');
}

[robbiespeed]

+1

[pixelhandler]

@rwjblue can this be closed? since #12686 prevents undefined and null from generating an htmlsafe warning

[rwjblue]

Yep, thanks @pixelhandler!