Comboboxes with different data stores fail.

[haysmark]

ComboBox? needs to instantiate its query. In Jared's dojox data store tests, ComboBoxes? that shared the same query but had different data stores (xml and json specifically) were failing. The current code needs a slight tweak to work 100%. Here is what should be there:

if(this.query==dijit.form.ComboBoxMixin.prototype.query){this.query={};}

[Douglas Hays]

(In [9938]) Fixes #3962. Proxy commit for haysmark. ComboBox? instantiates its query object.

[haysmark]

Wait, Adam already fixed this . . .