PlotLane: Use identity hashCode and equals

Using the lane position and other data for equals/hashCode is not
useful.

Change-Id: I7af151d8a84544a77a486474c8ac71dd80090c66
Signed-off-by: Konrad Kügler <swamblumat-eclipsebugs@yahoo.de>

org.eclipse.jgit.ui/src/org/eclipse/jgit/awtui/SwingCommitList.java

@@ -83,14 +83,5 @@ class SwingCommitList extends PlotCommitList<SwingCommitList.SwingLane> {
 
 	static class SwingLane extends PlotLane {
 		Color color;
-		@Override
-		public boolean equals(Object o) {
-			return super.equals(o) && color.equals(((SwingLane)o).color);
-		}
-
-		@Override
-		public int hashCode() {
-			return super.hashCode() ^ color.hashCode();
-		}
 	}
 }

org.eclipse.jgit/src/org/eclipse/jgit/revplot/PlotCommitList.java

@@ -236,7 +236,6 @@ public class PlotCommitList<L extends PlotLane> extends
 			if (newPos == -1)
 				newPos = positionsAllocated++;
 			freePositions.add(Integer.valueOf(commit.lane.getPosition()));
-			activeLanes.remove(commit.lane);
 			commit.lane.position = newPos;
 			activeLanes.add(commit.lane);
 		}

org.eclipse.jgit/src/org/eclipse/jgit/revplot/PlotLane.java

@@ -63,12 +63,4 @@ public class PlotLane implements Serializable {
 	public int getPosition() {
 		return position;
 	}
-
-	public int hashCode() {
-		return position;
-	}
-
-	public boolean equals(final Object o) {
-		return o == this;
-	}
 }