Implementation for FLUID-3711

[Antranig Basman]

At length I have come up with an implementation of FLUID-3711/FLUID-3708 
that apppears to work under NVDA. A lot of my initial problems seem 
caused by the fact that live regions simply do not function at all with 
NVDA under Windows 2000, which is the OS I have in my VM. Switching to 
Windows XP allows at least some functionality for live regions - however 
some aspects of ARIA still seem broken, for example audible feedback for 
progress bars. We will most likely be looking at this issue wrt. the 
Uploader today. I am using the stable "2010.2" release of NVDA for testing.

http://issues.fluidproject.org/browse/FLUID-3711

A patch is attached to this issue which implements the required 
functionality, with the odd caveat that NVDA needs to be put into 
something called "focus mode" when operating the reorderer (this is 
apparently completely unrelated to the labelling function of the patch) 
otherwise the reorderer and browser will go bananas as they fight with 
NVDA over the binding of the arrow keys and TAB key. I presume this is a 
known issue with the reorderer.

We should consider whether it's still appropriate at this point in the 
release cycle to commit this patch, and whether also to dedicate the 
resources to test whether it is functional under JAWS also.

Cheers,
Antranig.