Bug 22467 TextEdits: replace != delete + insert
see TextBufferTest.testReplaceAndInsert1
org.eclipse.jdt.ui.tests/ui/org/eclipse/jdt/ui/tests/core/TextBufferTest.java
MoveTextEdit e2= new MoveTextEdit(5, 2, 1);
		fEditor.add(e1);
		fEditor.add(e2);
		assertTrue("Can perform edits", fEditor.canPerformEdits());
		UndoMemento undo= fEditor.performEdits(null);
		assertEquals("Buffer content", "0561472389", fBuffer.getContent());
		doUndo(undo);		
	}
	
	public void testSwap1() throws Exception {
		SwapTextEdit e1= new SwapTextEdit(1, 1, 3, 1);
		fEditor.add(e1);
		assertTrue("Can perform edits", fEditor.canPerformEdits());
		UndoMemento undo= fEditor.performEdits(null);
		assertEquals("Buffer content", "0321456789", fBuffer.getContent());
		doUndo(undo);
	}
	
	public void testSwap2() throws Exception {
		SwapTextEdit e1= new SwapTextEdit(1, 1, 3, 1);
		SwapTextEdit e2= new SwapTextEdit(5, 1, 7, 1);
		fEditor.add(e1);
		fEditor.add(e2);
		assertTrue("Can perform edits", fEditor.canPerformEdits());
		UndoMemento undo= fEditor.performEdits(null);
		assertEquals("Buffer content", "0321476589", fBuffer.getContent());
		doUndo(undo);
	}
	
	public void testSwap3() throws Exception {