Fixes to cope with latest Dijit changes.

There were three issues:

1. `_setterAttrs` changed to `_props` (As Bill found)
2. Stopped support of per-instance `_setXXXAttr()`
3. Apparent removal or auto-mapping of `value` to `focusNode.value`

As to 2.: I ended up with coping some lines of code from _WidgetBase. Though I guess _WidgetBase hasn't ever explicitly supported per-instance `_setXXXAttr()`, it'd be nice if we can get the support back.