Multiple changes:
- actions are now available unconditionally, but only work in the right
state. This mirrors other actions.
- instead of adding actions manually, they invoke the action on the
GtkCellAccessibleParent interface.
Tests have been updated to reflect the changes
This drops the AtkText implementation, and also strips handling
of children out. Instead of listening for enter/leave/press/released,
just listen for state changes on the widget.
At the same time, drop the AtkText implementation.
Also, reintroduce a GtkBoxAccessible, since the previous
way of setting the role in get_accessible was affecting
GtkBox subclasses negatively.
Adjust expected test output to match.
Selection count is tested via assertions and can be inferred from
looking at the number of selected children.
And I'd like to reduce the output of the tests. We're outputting way too
much anyway.
