SplitContainer: extra slider/handle appears

[bill]

In ​http://archive.dojotoolkit.org/nightly/dojotoolkit/dijit/tests/layout/test_LayoutCode.html (tested on FF2/Mac), click "Split Layout" button and then notice (and fix) the strange short lines:

• short vertical line at beginning of text string "left pane of split container"
• short horizontal line at beginning of text string "center-top pane of nested split container"

[guest]

May be related to this:

The call: <code> widget.addChild(createWidgetHierarchy(child)); </code> fails if called before <code> widget.startup(); </code>

Calling widget.startup just after widget creation seems to work <code> var widget = new dijit.layout[widgetJson.widgetType](widgetJson.params, node); widget.startup(); TODO: this is required now, right? </code>

[bill]

(In [10246]) Fixes #3623: SplitContainer?: extra slider/handle appears.

If addChild() is called before startup() then it shouldn't do much of anything, because startup() is going to go through every child widget. In this case, we were getting too many splitters (we were getting (n-1)*2 rather than n-1).