Develop hierarchical table UI component

User Interface Changes

From a high level, one way to look at what we're trying to accomplish here is to take the existing table in categoryEdit.jspf and make it hierarchical with sub-tables brought over from overview.jsp.

To do this and stay within the general structure it's probably going to be necessary to create a new HtmlDataTableTag and Renderer for this new hierarchical table. It might be possible to do this by cannibalizing GradebookItemTableTag.java, and GradebookItemTableRenderer.java

The GradebookSetupBean.java will need to populate a gradebookItemList. There is currently some logic to do this in the init() method of OverviewBean.java. Other tasks include putting in the accessors on that bean to manage sort logic, appropriate navigation links, permission booleans, etc.