[orca-list] Making changes to selection support for web content

[Joanmarie Diggs <jdiggs igalia com>]

Hey all.

I just wanted to give you a heads up that I am currently doing work on 
Orca's presentation of text selection changes. There are some known 
issues with things not being presented. I am still working on these 
issues. However, given the improvements in overall reliability and 
performance, I went ahead and committed the changes. If I've broken 
something horribly, please let me know. If I just need to keep improving 
things and fixing those remaining issues, please be patient. :)

Lastly, please note that the way Orca handles text selection is to let 
the browser control the caret and selection. This is because we need 
changes made to ATK, AT-SPI2, and the browsers before Orca can control 
selection itself. This means that Orca has no way to control what gets 
selected or where you land as a result of using Shift + cursor keys.

--joanie