ComboBox.js hard coded classes

[dante]

Trying to subclass ComboBox became difficult when trying to connect to the popup, which uses the class dijit.form._ComboBoxMenu ...

suggest using a private _popupClass (as _popupWidget is in use) and using dojo.getObject to allow uses to plugin more easily.

[dante]

might drop back to 1.3 if these kinds of changes are on the 1.3 radar.

[bill]

bumping 1.4 tickets to 1.5, and most 1.3 tickets to 1.4

[dante]

so this actually falls second to a larger plan I want to implement:

• enforce a rule like this everywhere. "no hard coded classes"
• use a cache of getObject lookups to only lookup once (parser has instanceClasses[i].cls already

[dante]

so I'm going to move this to the 2.0/ambigious future milestone for lack of a better place to put them. In Dojo 2.0, we should normalize passing an object/function reference or string (eg: dojo.fx.easing.backOut) and Dijit should have some kind of getObject() cache (like dojo.parser does). This generalization covers all "hard-coded-classes" tickets. We should be able to pass a string (dojo.getObject) without taking ANY performance hit, a direct object (the fast path), or have sane defaults.

[bill]

(In [22674]) Ability to specify separate class for ComboBox drop down menu. Fixes #6054 !strict.