JOSM exit;unsaved changes dialog

[sascha-web-josm.openstreetmap.de@…]

On exiting without saving JOSM asks "There are unsaved changes. Discard the changes and continue?", giving Yes and No as options. This is highly dangerous, as several other applications use similar dialogs, but some of them with negated options ("Save before exiting?").
A better way to handle it is to name the buttons according to their result, like Gimp does:

Save the changes to image 'Untitled' before closing?
If you don't save the image, changes from the last XX seconds will be lost.

![Don't save] ![Cancel] ![Save]

While giving the last modification time is useful to determine if the last change was accidental or intentional, it's not absolutely necessary.
The following text might suit JOSM:

You have made changes since you last saved or uploaded. If you exit without saving, these changes will be lost forever.

![Save locally] ![Discard changes] ![Don't exit]

I haven't worked with Swing before (only SWT), so no patch, sorry.

[Hasienda]

consider a recent, duplicate ticket #1770, that proposes three buttons:

<Save then quit> <Quit without saving> <Cancel>

[xeen]

This patch is on top of #1977 and adds the possibility to save changes before exiting. On a second thought it should be better to make "save" the default action though as proposed above.

[xeen]

Same as above but with Save and Exit actions switched

[anonymous]

Fixed in r1373.