some bug fix

 - bug fix with browse-kill-ring-update
 - bug fix with browse-kill-ring-delete
 - works with delete-selection-mode
modify save-and-restore option when exit.

use quit-window when emacs version is 24+.
Merge pull request #17 from skyer9/patch-2

some bug fix
Set RET to `browse-kill-ring-insert-move-and-quit'

Pull Request by skyer9:
Swap RET (for `browse-kill-ring-insert-move-and-quit') and u key bindings.
When kill is selected from browse-kill-ring (by typing RET),
selected kill is changed to last kill of kill-ring,
and can yank selected kill directy.