[orca-list] Bug fixes for Gecko content landed in master

[Joanmarie Diggs <jdiggs igalia com>]

Hey all.

I'm in the process of merging fixes for Gecko content into master. I've
just committed the first bit of work. It should fix:

  * Not presenting the last line in a text area
  * Not repositioning location at newly-loaded fragment (same page link)
  * Not presenting expanded state change in ARIA content
  * Not presenting correct radio button state in ARIA content
  * Several issues related to pyatspi cache not being updated
  * Double-presenting find results
  * Re-generating braille when not needed

And hopefully not introduce regressions. But it's a big change so
testing of master is appreciated. If you find a bug, please then test
the revision prior to this commit to see if it's a regression or an
existing bug.

Lastly, there are other fixes to come which will improve performance and
fix other bugs. But I'm trying to do this in manageable stages.

Thanks!
--joanie