refactor and improve naming

Signed-off-by: Florian Thienel <florian@thienel.org>
diff --git a/org.eclipse.vex.core/src/org/eclipse/vex/core/internal/undo/AbstractUndoableEdit.java b/org.eclipse.vex.core/src/org/eclipse/vex/core/internal/undo/AbstractUndoableEdit.java
index 43bfb07..67248c9 100644
--- a/org.eclipse.vex.core/src/org/eclipse/vex/core/internal/undo/AbstractUndoableEdit.java
+++ b/org.eclipse.vex.core/src/org/eclipse/vex/core/internal/undo/AbstractUndoableEdit.java
@@ -24,7 +24,7 @@
 	private boolean hasBeenDone = false;
 
 	@Override
-	public boolean combine(final IUndoableEdit edit) {
+	public final boolean combine(final IUndoableEdit edit) {
 		if (hasBeenDone) {
 			return performCombine(edit);
 		}
@@ -44,7 +44,7 @@
 	}
 
 	@Override
-	public void redo() throws CannotApplyException {
+	public final void redo() throws CannotApplyException {
 		if (!canRedo()) {
 			throw new CannotApplyException();
 		}
@@ -66,7 +66,7 @@
 	protected abstract void performRedo() throws CannotApplyException;
 
 	@Override
-	public void undo() throws CannotUndoException {
+	public final void undo() throws CannotUndoException {
 		if (!canUndo()) {
 			throw new CannotUndoException();
 		}
@@ -95,5 +95,4 @@
 	public boolean canRedo() {
 		return !hasBeenDone;
 	}
-
 }
\ No newline at end of file
diff --git a/org.eclipse.vex.core/src/org/eclipse/vex/core/internal/undo/CompoundEdit.java b/org.eclipse.vex.core/src/org/eclipse/vex/core/internal/undo/CompoundEdit.java
index adf63da..a47196a 100644
--- a/org.eclipse.vex.core/src/org/eclipse/vex/core/internal/undo/CompoundEdit.java
+++ b/org.eclipse.vex.core/src/org/eclipse/vex/core/internal/undo/CompoundEdit.java
@@ -20,11 +20,7 @@
  */
 public class CompoundEdit extends AbstractUndoableEdit {
 
-	/**
-	 * Class constructor.
-	 */
-	public CompoundEdit() {
-	}
+	private final List<IUndoableEdit> edits = new ArrayList<IUndoableEdit>();
 
 	/**
 	 * Adds an edit to the list.
@@ -72,7 +68,4 @@
 		return true;
 	}
 
-	// ===================================================== PRIVATE
-
-	private final List<IUndoableEdit> edits = new ArrayList<IUndoableEdit>();
 }