Lister window destroy interface.

[nyam]

When closing lister window,
There'll be three method.

Method 1. Close button click
Method 2. 'Q' key
Method 3. 'Escape' key(File->Close)

Method 1 and Method 2 generate WM_CLOSE. (It is natural for Method 1.)
But, Method 3 doesn't generate WM_CLOSE.

I can't process WM_CLOSE before closing plugin window.
(Not WM_DESTROY...)

Dear Ghisler, Could you unify the method of closing lister to generate WM_CLOSE message?

[ghisler(Author)]

Hmm, it's odd why ESC doesn't use WM_CLOSE - I will check it.