[ALOY-1477] Regression: Missing model attributes cause error on collection data binding

<Alloy>
	<Model src="mymodel" />
	<Collection src="mymodel" />
	<Window>
		<ScrollView layout="vertical">
			<Label top="30" text="{mymodel.id} - {mymodel.title}" />
			<ListView>
				<ListSection dataCollection="mymodel">
					<ListItem title="{id} - {title}" />
				</ListSection>
			</ListView>
			<Button onClick="createModel">Create Model</Button>
		</ScrollView>
	</Window>
</Alloy>

Alloy.Models.mymodel.set({
  id: 0,
  title: 'mod TITLE'
});

Alloy.Collections.mymodel.reset([{
  id: 0,
  title: 'col TITLE'
}]);

$.index.open();

function createModel() {
  Alloy.Collections.mymodel.create({
    title: 'crt TITLE'
  });
}

exports.definition = {
  config: {
    "columns": {
      "id": "INTEGER PRIMARY KEY AUTOINCREMENT",
      "title": "TEXT"
    },
    "adapter": {
      "type": "sql",
      "collection_name": "mymodel",
      "idAttribute": "id"
    }
  }
};

[INFO]  var __t,__p='',__j=Array.prototype.join,print=function(){__p+=__j.call(arguments,'');};
[INFO]  with(obj||{}){
[INFO]  __p+='{mymodel.id} - {mymodel.title}';
[INFO]  }
[INFO]  return __p;
[INFO]
[INFO]  var __t,__p='',__j=Array.prototype.join,print=function(){__p+=__j.call(arguments,'');};
[INFO]  with(obj||{}){
[INFO]  __p+=''+
[INFO]  ((__t=(id))==null?'':__t)+
[INFO]  ' - '+
[INFO]  ((__t=(title))==null?'':__t)+
[INFO]  '';
[INFO]  }
[INFO]  return __p;

[ERROR] Script Error {
[ERROR]     column = 10;
[ERROR]     line = 4;
[ERROR]     message = "Can't find variable: id";