Option role: Change aria-selected from required to supported and remo…

…ve implicit value

For issue #700, made the following changes to the option role section in index.html:

1. Remove sentence from description that states there is an default value of false fore aria-selected on option elements.
2. Remove aria-selected from required states and properties row of attributes table.
3. Add aria-selected to supported row of attributes table.
4. Remove default value for aria-selected from implicit values row of attributes table.

Note: This cascades to treeitem so that aria-selected is not required on treeitem.

index.html

@@ -4679,7 +4679,6 @@ <h5>Note regarding the ARIA 1.1 <code>none</code> role.</h5>
 			<div class="role-description">
 				<p>A selectable item in a <rref>select</rref> list.</p>
 				<p>Authors MUST ensure <a>elements</a> with <a>role</a> <code>option</code> are contained in, or owned by, an element with the <a>role</a>  <rref>listbox</rref> or <rref>group</rref>. Options not associated with a <rref>listbox</rref> might not be correctly mapped to an <a>accessibility <abbr title="Application Programing Interfaces">API</abbr></a>.</p>
-				<p>Elements with the role <code>option</code> have an implicit <sref>aria-selected</sref> value of <code>false</code>.</p>
 			</div>
 			<table class="role-features">
 				<caption>Characteristics:</caption>
@@ -4730,11 +4729,7 @@ <h5>Note regarding the ARIA 1.1 <code>none</code> role.</h5>
 					</tr>
 					<tr>
 						<th class="role-required-properties-head">Required States and Properties:</th>
-						<td class="role-required-properties">
-							<ul>
-								<li><sref>aria-selected</sref></li>
-							</ul>
-						</td>
+						<td class="role-required-properties"></td>
 					</tr>
 					<tr>
 						<th class="role-properties-head" scope="row">Supported States and Properties:</th>
@@ -4743,6 +4738,7 @@ <h5>Note regarding the ARIA 1.1 <code>none</code> role.</h5>
 								<li><sref>aria-checked</sref></li>
 								<li><pref>aria-posinset</pref></li>
 								<li><pref>aria-setsize</pref></li>
+                <li><sref>aria-selected</sref></li>
 							</ul>
 						</td>
 					</tr>
@@ -4777,7 +4773,7 @@ <h5>Note regarding the ARIA 1.1 <code>none</code> role.</h5>
 					</tr>
 					<tr>
 						<th class="implicit-values-head" scope="row">Implicit Value for Role:</th>
-						<td class="implicit-values">Default for <sref>aria-selected</sref> is <code class="default">false</code>.</td>
+						<td class="implicit-values"></td>
 					</tr>
 				</tbody>
 			</table>