Integrated UI patch

["Patrick Hallinan" <patrick j hallinan gmail com>]

Hi,

This patch 

-Fixes the problem with the active diagram changing during resize
-Adds an asterisk to the tab to show  that a diagram  has been modified.
-Adds a new dialog to give the user the ability to choose which unsaved files to save at exit.

The bulk of the patch is the new files exit_dialog.c and exit_dialog.h

Attachment: dia.patch
Description: Text Data