Bug 100889 [Undo] - AbstractOperation toString() appends bogus comma
The toString() on AbstractOperation puts commas between undo contexts, and also puts one at the end. It looks pretty bogus in the operation history view. Should clean up to not add the very last comma.
bundles/org.eclipse.core.commands/src/org/eclipse/core/commands/operations/AbstractOperation.java
*      org.eclipse.core.runtime.IAdaptable)
	 */
	public abstract IStatus execute(IProgressMonitor monitor, IAdaptable info)
			throws ExecutionException;
	public final IUndoContext[] getContexts() {
		return (IUndoContext[]) contexts.toArray(new IUndoContext[contexts
				.size()]);
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.core.commands.operations.IUndoableOperation#getLabel()
	 *      <p> Default implementation. Subclasses may override this method.
	 *      </p>
	 */
	public String getLabel() {
		return label;
	}
	/**
	 * Set the label of the operation to the specified name.
	 * 
	 * @param name
	 *            the string to be used for the label.
	 */
	public void setLabel(String name) {
		label = name;
	}
	/*
	 * (non-Javadoc)
	 *