Enabled double click for buttons.

diff --git a/controls/button.c b/controls/button.c
index 1fd7798..9f988db 100644
--- a/controls/button.c
+++ b/controls/button.c
@@ -126,6 +126,7 @@
         break;
 
     case WM_LBUTTONDOWN:
+    case WM_LBUTTONDBLCLK:
         SendMessage32A( hWnd, BM_SETSTATE32, TRUE, 0 );
         SetFocus32( hWnd );
         SetCapture32( hWnd );