dojox.mvc.Output cannot display binding data when the data value is 0

[Eric Wang]

Use dojox.mvc.Output to display value like this:

<span data-dojo-type="dojox.mvc.Output" data-dojo-props="ref: 'priority'">Priority: ${this.value}</span>

if priority=0, this span will display nothing after Priority: , However we expect it display Priority: 0

[cjolif]

In [27682]:

fixes #14424, #14445, #14444. Thanks edchat. !strict.