Added expand.
Added expand.

Use this.start.node.ownerDocument instead of simply document, so that ranges from other
browser context (window objects) can be manipulated correctly (e.g. when manipulating
a range from the test harness script).

corinthia/corinthia-editorlib,corinthia/corinthia-editorlib,corinthia/corinthia-editor,corinthia/corinthia-editorlib,corinthia/corinthia-editorlib,corinthia/corinthia-editor,corinthia/corinthia-editor,corinthia/corinthia-editor,corinthia/corinthia-editor,corinthia/corinthia-editorlib