Bug 200471 Add "need not sort for grouping" option in report item
Currently when Data engine proceeds groups, it always sorts the result set according to given group key.However that should not be necessary when the raw data is already sorted. So we'd like to add new options so that user can indicate whether should we sort the data before grouping. In model, we should allow user to set a "need not do sort for grouping" option to all the report element that can be grouped(table, list,etc.)
model/org.eclipse.birt.report.model.tests/test/org/eclipse/birt/report/model/parser/TableItemParseTest.java
* <code>TableColumn</code>,<code>TableRow</code> and <code>Cell</code>
 * are tested in {@link GridItemParseTest}.
 * 
 * <p>
 * <table border="1" cellpadding="2" cellspacing="2" style="border-collapse:
 * collapse" bordercolor="#111111">
 * <th width="20%">Method</th>
 * <th width="40%">Test Case</th>
 * <th width="40%">Expected</th>
 * 
 * <tr>
 * <td>{@link #testParser()}</td>
 * <td>Test all properties and slots of <code>TableItem</code> after parsing
 * design file</td>
 * <td>All properties are right</td>
 * </tr>
 * 
 * <tr>
 * <td></td>
 * <td>Test all properties of Sorting after parsing design file</td>
 * <td>Sorting is not implemented</td>
 * </tr>
 * 
 * <tr>
 * <td></td>
 * <td>Test all properties of <code>TableGroup</code> after parsing design
 * file</td>
 * <td>All properties are right</td>
 * </tr>
 *