new "Add layout" dialog

["Sergey Udaltsov" <sergey udaltsov gmail com>]

Hi all

Here is the mockup (actually 80% functional) of the new layout chooser dialog:

http://www.gnome.org/~svu/ladd.png

I got rid of the layouts/variants tree which confused a lot of people
- instead, there are 2 GtkComboBoxEntries.
The only real problem for me now is how to indicate the default
variant - which is a special case (and I would prefer to have it on
the top of the list). Unfortunately combo boxes do not understand the
markup, so I cannot even make it italic or bold.

Any ideas/comments would be welcome.

Cheers,

Sergey