ACTION-2105: Do a ¨net change¨ list in preparation for test case development

[MichaelC]: talk with Joanie about this

Here's my first pass at it:

===========================================
Introduced in 1.1 and requires full testing
===========================================

States and properties:
* aria-current
* aria-colcount
* aria-colindex
* aria-colspan
* aria-details
* aria-errormessage
* aria-keyshortcuts
* aria-modal
* aria-placeholder
* aria-roledescription
* aria-rowcount
* aria-rowindex
* aria-rowspan

Roles:
* Cell
* Feed
* Figure
* None
* Searchbox
* Switch
* Table
* Term

==============
Changed in 1.1
==============

* aria-activedescendant added as supported property of application

* aria-busy is (more clearly) applicable to all elements. Note that
this technically was the case for 1.0. But the text in 1.0 implies
busy was intended for live regions.

* aria-controls went from supported to required on combobox

* aria-expanded removed as a supported property of separator

* aria-haspopup type is now token. Values:
* true
* false (default, unless it's a combobox)
* menu
* listbox (default for combobox)
* tree
* grid
* dialog

* aria-hidden's type is now true/false/undefined
* undefined is new default
* undefined means user agent determines state based on rendering

* aria-level's implicit value for heading is now 2

* aria-orientation's default value changed from horizontal to undefined
* scrollbar now has implicit value of vertical
* slider now has implicit value of horizontal
* separator now has implicit value of horizontal
* aria-orientation added to:
* combobox
* listbox, implicit value: vertical
* menu, implicit value: vertical
* menubar, implicit value: horizontal
* radiogroup
* tablist, implicit value: horizontal
* toolbar, implicit value: horizontal
* tree, implicit value: vertical
* treegrid, implicit value: undefined

* aria-posinset and aria-setsize added to:
* article (when article is in feed)
* menuitem
* menuitemcheckbox
* menuitemradio
* tab

* aria-readonly added as supported property of:
* checkbox
* combobox
* listbox
* menuitemcheckbox
* menuitemradio
* radiogroup
* slider
* spinbutton

* aria-selected
* removed from radio
* required (as opposed to supported) for treeitem

* aria valuetext added as a supported property of focusable
separators

* aria-valuemin, aria-valuemax, aria-valuenow added as required
properties of focusable separators

* aria-valuemin now has an implicit value on some roles:
* scrollbar is 0
* separator is 0
* slider is 0
* spinbutton is "that there is no minimum value"

* aria-valuemax now has an implicit value on some roles:
* scrollbar is 100
* separator is 100
* slider is 100
* spinbutton is "that there is no maximum value"

* aria-valuenow now has an implicit value on some roles:
* scrollbar is half way between aria-valuemin and aria-valuemax
* separator is 50
* slider is half way between aria-valuemin and aria-valuemax
* spinbutton is 0

* children-presentation added to:
* checkbox
* menuitemcheckbox
* menuitemradio
* option
* radio
* tab

* name from contents removed from:
* directory
* listitem

* role changes:
* application is no longer a landmark
* region is now a landmark
* spinbutton subclasses composite and can have children

===================================================
Testable user agent normative statements not in 1.0
===================================================

* Applying the aria-selected state on a columnheader MUST not cause
the user agent to automatically propagate the aria-selected state
to all the cells in the corresponding column.

* User agents SHOULD not expose (aria-readonly or aria-required) to
assistive technologies unless the columnheader descends from a grid.

* The previous requirement is also stated for role rowheader.

* If aria-readonly is set on an element with role grid, user agents
MUST propagate the value to all gridcell elements owned by the grid
and expose the value in the accessibility API. An author may override
the propagated value of aria-readonly for an individual gridcell
element.

* The previous requirement is also stated for role treegrid.

* The ARIA 1.0. specification describes a combobox pattern where a text
input element has the combobox role and owns a listbox element. User
agents, assistive technologies, and conformance checkers SHOULD
continue to support the ARIA 1.0 pattern.

* User agents MUST treat any value of aria-haspopup that is not
included in the list of allowed values, including an empty string,
as if the value false had been provided.

* To provide backward compatibility with ARIA 1.0 content, user agents
MUST treat an aria-haspopup value of true as equivalent to a value
of menu.

(Sorry for the formatting issue. I forgot that space chars got nuked by tracker.)

Content moved to https://www.w3.org/WAI/ARIA/wiki/ARIA_1.1_Changes