[5c01ea] ARIA state or property is permitted - Passed Example 6-7-8-10-12 improvement

[shunguoy]

In ARIA state or property is permitted, Passed Examples 6, 7, 8 and 10
do not fully adhere to the ARIA specifications for required and supported states and properties.

1. The only required state and property for the combobox role is area-expanded, the aria-controls is no longer required. This applies to the examples 6, 7, and 8. The descriptions and the code for those examples need to be updated.

2. The role='none' is invalid for a button element per ARIA in HTML. Thus, the description and code for the example need to be updated.
   ACT rules are cool!

3. remove aria-hidden="true" from example 12 because of the explicit style="display: none;".
   On