Bug 246120

Description of problem:
I occasionally hit Ctrl-W when trying to hit Ctrl-E; closing the main evolution
window, rather than expunging the folder.

I have several composer windows open, and a dialog pops up for one of them: 

"Warning: Modified Message

Are you sure you want to discard the message, titled 'Foo', you are composing?

Closing this composer window will discard the message permanently, unless you
choose to save the message in your Drafts folder. This will allow you to
continue the message at a later date.
[Discard Changes] [Cancel] [Save Message]"

On hitting Cancel, it doesn't immediately cancel the quit, instead, I get a
similar dialog for each open message, and have to click cancel in each one.

Version-Release number of selected component (if applicable):
evolution-2.8.0-33.el5

How reproducible:
100%

Steps to Reproduce:
1.  In evolution mailer, click on File->New->Mail Message several times
2.  Click on File->Exit
3.  In "Warning: Modified Message" dialog, click on Cancel
  
Actual results:
More "Warning: Modified Message" dialogs appear, for each open message, and I
have to cancel each one.

Expected results:
Upon clicking Cancel on any of the dialogs, the Quit verb should be cancelled,
and I shouldn't have to deal with any more confirmation dialogs.