This duplicates the current test with a GtkTreeStore instead
of a GtkListStore.

Avoid many unnecessary list iterations by using a hash table
to store cell infos, and caching row and column counts. Based
on patches by William Jon McCann, bug 554171.

tree-performance results:

before:  (MINPERF:large tree test with a11y: 9.18531sec)
after:   (MINPERF:large tree test with a11y: 0.923463sec)

for comparison, without accessibility:
(MINPERF:large tree test: 0.016179sec)

This test creates a treeview with a few columns and a liststore,
and then populates it with a 1000 rows.

...and when you do pass them a real string, don't leak it.

THe testcase depends on the installed printers, so is nondeterministic.

This reverts commit 5bf14cc7485fe015ad15747454e877f2fb3dabc5.

File choosers depend on the files in the current directory and the
settings the user has set for the file chooser, so the output cannot be
deterministic.

This reverts commit f05c9e02c49f857c33e02c3d89483fcccb5df254.

The font chooser depends on the fonts installed on the system, so the
output is nondeterministic.

This reverts commit 08fdc399762c2af07d94e42a1801e691e5d4d6ab.

This guarantees that objects are named the same all the time.

As set_description is never called and unsupported by the at-spi, we can
omit implementing it.
This means we can also omit get_description calls in various places, as
they'd just return the default value: NULL.

This code was supposed to work around a bad interaction between GOK and
Nautilus from 7 years ago.
If it still exists, the GOK developers may complain to the Nautilus
developers.

https://bugzilla.gnome.org/show_bug.cgi?id=137401

The ATK default code does the same thing as these two functions.

This had crept into the expected output for the buttons
testcase.

...and when there are pixbufs, don't leak them.

This ensures that libgtk gets relinked when I touch sources
in gtk/a11y.

We are still hitting the 'no name' case in GtkFileChooser for
a GailBox, otherwise.

We do this by transforming the returned GValue to a string.
As a side-effect, the formatting for doubles changes, so
adjust expected output to match.