[patch][ccla]dojox.widget.Toaster add keyboard and screen reader support

[mikeb]

Make dojojx.widget.Toaster more accessible by:

1. Setting aria-role="status" to the Toaster messages. This way messages are announced "politely" by the screen reader.

2. Setting tabindex=0 on the messages, which allows users to use tab into the messages. This way they can read all of the messages by pressing the Down Arrow(JAWS) or they can close the Toast by pressing Enter.

3. Setting aria-label on the toaster to give instructions to screen reader users.

There is a weird issue where JAWS13 will only read the status if there are at least 2 messages "stacked up", and a related issue where it then reads the previous message and the current message. This might be an issue with JAWS13 or how users have configured their screen reader. I tried applying role="status" to the different nodes and could not get rid of this behavior; it needs deeper investigation that we can track here. Until then screen reader users can still access the toaster messages by tabbing in and pressing the down arrow to read all of the messages.

Also, it should be noted that the WAI-ARIA spec says that if another part of the page controls what appears in the status (toast), authors SHOULD make the relationship explicit with the aria-controls attribute.

CCLA on file with IBM

[mikeb]

adds keyboard and aria support

[Douglas Hays]

This patch has aria-label hardcoded in English in the template, and also after processing the ENTER key, it doesn't do preventDefault() which could cause an outer FORM element to submit.

[dylan]

This patch would need to address doughays' comments, and also make sure it's updated for latest AMD and html5 data-* attrs, as well as recent APIs like on instead of connect.

[trac-o-bot]

Because we get so many tickets, we often need to return them to the initial reporter for more information. If that person does not reply within 14 days, the ticket will automatically be closed, and that has happened in this case. If you still are interested in pursuing this issue, feel free to add a comment with the requested information and we will be happy to reopen the ticket if it is still valid. Thanks!