Calendar: can't keyboard navigate past disabled dates (or months?)

[bill]

On test_DateTextBox.html, in the "american" calendar, use ctrl-page-down key to get to 2007. Selection is lost and you can't navigate past 2007. This would be problematic if there were selectable dates in 2008: the keyboard user can't get to them.

A related strange behavior is that the ctrl-page-up button will go directly back to 2005, skipping 2006.

Note: due to #11483 try this on another browser/os than FF/mac.

[bill]

(In [22561]) Keyboard tests for DateTextBox, working around the known issue #11483, #11484, and the lack of key repeat support. Should add tests for navigation across disabled dates, and for key repeat, after those features are working. Refs #6430, #9918, #11483, #11484.

[bill]

Note: workaround code in DateTextBox.html is:

// year changed
// due to #11484 this selects 2005 rather than 2006
...
doh.is("2005", innerText(selectedYearButtons[0]), "year changed");
calendar.set("value", new Date(2006, 5, 18));

Above that there's also combination workaround code for #11483 and #11484:

if(dojo.isMac && dojo.isFF){
	// doesn't work on mac/FF, see #11483
	doh.robot.sequence(d.getTestErrback(function(){
		calendar.set("value", new Date(2005, 5, 18));	// see #11484
}), 500);

[bill]

(In [22665]) Calendar: separate focus and selection handling, so that (like ColorPalette and Tree), arrow keys navigate and ENTER/SPACE selects the date (fixes #10001 !strict). This allows navigation across disabled dates (refs #6430, fixes #11484), and completes keyboard support for DateTextBox, although it still needs screen reader work (refs #9918).

Also seems to have fixed the ctrl-page-up/down problem on FF/mac (fixes #11483).

Also merged in Calendar.set("value", ..., priorityChange) support from neonstalwart (fixes #11331), thanks!