[orca-list] More and significant fixes for Gecko committed to master

[Joanmarie Diggs <jdiggs igalia com>]

Hey all.

I've just committed the next set of fixes for Gecko to master. It's
another pretty big change, so thorough testing is greatly appreciated.
The list of fixes is below. But the most notable one -- pending your
confirmation -- is that Orca should no longer be confused by multiple
Firefox windows and should present the content of the active window and
page tab. Please let me know what you find.

Fixes:
* Performance through caching return values of frequently-called methods
* Present "link" when arrowing into text descendants of links
* Display inferred labels for radiobuttons and checkboxes in same
  order as if they were proper labels
* Increase consistency between presentation of ARIA and native apps
* Eliminate more unnecessary braille refreshing
* Stop presenting content from the wrong document frame / window
* Stop presenting images which are not rendered and have no alt text
* Stop double-presenting inferred labels in SayAll
* Present "link" as part of the same utterance when navigating by line
* Fix bogus duplicate characters in braille
* Fix treating inline block spans displayed on a single line as if they
  were on multiple lines

Thanks!!
--joanie