update some dijit infrastructure tests to AMD, stop using dojo/ready, prefer _WidgetBase to _Widget except when testing deprecated functionality, etc., refs #14279
add missing (indirect) dependency from dijit/Tree to dojo/query, needed since on.selector() used with a string for the selector, refs #16561 !strict
Fixes #16422.  Don't hide invalid option label in Select.
Fixes #16514.  Found that [].concat(val) is great for converting scalar or array values into arrays and works cross-frame.
since the parser will eventually only return a promise, start preparing for it now, refs #14591 !strict
remove dijit.js and dijit-all.js rollups, refs #1
remove deprecated layout modules (AccordionPane, LinkPane, SplitContainer), refs #1
remove deprecated _Calendar module, refs #1
remove dijit/WidgetSet deprecated module, refs #1
remove deprecated _BidiSupport module, refs #1
remove deprecated _Templated module, refs #1
_TemplatedMixin: remove support for templatePath etc., refs #4
_WidgetsInTemplateMixin: remove support for _earlyTemplatedStartup etc., refs #4
remove deprecated dijit/robotx module, should use dojo/robotx instead, refs #1
remove dijit/_base except for dijit/_base/manager::defaultDuration def, refs #1
Tree: remove support for dojo/data, direct store argument, etc., refs #4
remove dijit-legacy-requires, refs #4
[temporarily] stop loading _testCommon.js; it's based on dojo/ready and not easy to change
start removing _Widget, refs #1

Many of the modules converted to use _WidgetBase instead of _Widgetneed to be changed to include 	_OnDijitClickMixin, _FocusMixin, dojo/uacss, and dojo/hccss.
use dojo/Deferred not dojo/_base/Deferred, refs #4