New OverScroller with edge bouncing effect.

OverScroller has been made a Scroller child class. Both use a physical constant deceleration
force to compute the animation. OverScroller also includes a rubber edge bounce effect.

Approved by Jim Palmer.

Change-Id: I3f43a03694b8cb6bfa0784c2663b37c9c39322cc
diff --git a/core/java/android/view/View.java b/core/java/android/view/View.java
index 984e48b..7e748c0 100644
--- a/core/java/android/view/View.java
+++ b/core/java/android/view/View.java
@@ -5728,7 +5728,7 @@
      * of the thumb within the scrollbar's track.</p>
      *
      * <p>The range is expressed in arbitrary units that must be the same as the
-     * units used by {@link #computeHorizontalScrollRange()} and
+     * units used by {@link #computeVerticalScrollRange()} and
      * {@link #computeVerticalScrollOffset()}.</p>
      *
      * <p>The default extent is the drawing height of this view.</p>