Orca hard code freeze break request to handle impending Firefox changes

[Willie Walker <William Walker Sun COM>]

Hi All:

The pychecker fixes from earlier this week were the result of us looking
hard at some impending Firefox changes.  Thanks for letting us get those
in.  :-)  Now for the real problem...

We've been working with the Firefox team and the AT-SPI maintainers on
an approach to allow applications to more easily annotate an AT-SPI
event with additional information about why an event was generated.  In
the specific case we've been working on, we want to know if the event
was caused by an internal system change versus something that was
initiated by a user.  See
http://bugzilla.gnome.org/show_bug.cgi?id=475177.

The decision has been to append information to the event type string,
which works well.  The only problem is that Orca has a number of
equality checks for event types, which would cause annotated events to
be missed.  This means that Orca 2.20.0 would not work well with Firefox
3 unless we fix Orca.  The fix, which we should have been doing from the
start in Orca :-(, is to use a "startswith" check on the event type
instead of an equality check.  The patch at
http://bugzilla.gnome.org/show_bug.cgi?id=475177#c7 provides this
modification as well as a small change to help us verify the change via
regression testing.

We've been testing this patch pretty heavily, and are continuing to do
so today.  All is looking well, and I will only check things in on two
conditions: 1) you guys say this is OK, and 2) continued testing shows
that the patch works with the new and improved Firefox without
introducing any regressions.

OK to commit?

Will