Implemented Mousewheel support.

diff --git a/windows/input.c b/windows/input.c
index f124c0b..089e468 100644
--- a/windows/input.c
+++ b/windows/input.c
@@ -275,6 +275,11 @@
         hardware_event( WM_MBUTTONUP,
                         keyState, 0L, PosX, PosY, time, extra );
     }
+    if ( dwFlags & MOUSEEVENTF_WHEEL )
+    {
+        hardware_event( WM_MOUSEWHEEL,
+                        keyState, 0L, PosX, PosY, time, extra );
+    }
 }
 
 /***********************************************************************