Mouse wheel scrolls 3 lines at a time.

Index: trunk/src/ui/ui_shared.c
===================================================================
--- trunk/src/ui/ui_shared.c    (.../svn://svn.icculus.org/tremulous/trunk)    (revision 802)
+++ trunk/src/ui/ui_shared.c    (.../trunk)     (working copy)
@@ -1834,6 +1834,20 @@
       }
     }
     // mouse hit
+    if (key == K_MWHEELUP) {
+        listPtr->startPos-=3;
+        if (listPtr->startPos < 0) {
+          listPtr->startPos = 0;
+        }
+      return qtrue;
+    }
+    if (key == K_MWHEELDOWN) {
+        listPtr->startPos+=3;
+        if (listPtr->startPos > max) {
+          listPtr->startPos = max;
+        }
+      return qtrue;
+    }
     if (key == K_MOUSE1 || key == K_MOUSE2) {
       if (item->window.flags & WINDOW_LB_LEFTARROW) {
         listPtr->startPos--;
@@ -2381,7 +2395,7 @@
       }
     }
   }
-  DC->Print("slider handle key exit\n");
+  #DC->Print("slider handle key exit\n");
   return qfalse;
 }