Reverting to non-async file chooser

[Federico Mena Quintero <federico ximian com>]

Here's your bearer of bad news...

The async file chooser is extremely broken in gtk+-2.10 right now:

- Overwrite-confirmation doesn't work.

- Large chunks of the test suite just fail.  It looks like the automated
test suite never got run after the merge of the async code got done.

- It leaks async handles, doesn't have a clear policy for cancelation.

We don't want a stream of brown-bag 2.10.<low-digits> releases, so at
this point I'd rather revert the file chooser code and the libgnomeui
backend to the code that was in 2.8 --- that is, the non-async,
well-tested code.  I have very well tested code from the Novell package
for reference, which will still give us niceties such as a Location
entry in the dialog.

Thoughts?

  Federico