Bug 124067 When select the XML file, the relative path should be supported.
Description: When select the XML file, the relative path should be supported. Step to reproduce: 1. new a report 2. new a datasource and dataset based on a XML file 3. select the XML file, the file relative path should be used. Actual result: only the absolute path is supported. Expect result: the relative and absolute path are supported.
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/adapter/ModelDteApiAdapter.java
int exportHint = IColumnDefinition.DONOT_EXPORT; 
			if ( exportConstant
					.equals( DesignChoiceConstants.EXPORT_TYPE_IF_REALIZED ) )
				exportHint = IColumnDefinition.EXPORT_IF_REALIZED;
			else if ( exportConstant
					.equals( DesignChoiceConstants.EXPORT_TYPE_ALWAYS ) )
				exportHint = IColumnDefinition.ALWAYS_EXPORT;
			else
				assert exportConstant
						.equals( DesignChoiceConstants.EXPORT_TYPE_NONE );
			dteColumn.setExportHint( exportHint );
		}
		String searchConstant = modelColumnHint.getSearching( );
		if ( searchConstant != null )
		{
			int searchHint = IColumnDefinition.NOT_SEARCHABLE;
			if ( searchConstant
					.equals( DesignChoiceConstants.SEARCH_TYPE_INDEXED ) )
				searchHint = IColumnDefinition.SEARCHABLE_IF_INDEXED;
			else if ( searchConstant
					.equals( DesignChoiceConstants.SEARCH_TYPE_ANY ) )
				searchHint = IColumnDefinition.ALWAYS_SEARCHABLE;
			else
				assert searchConstant
						.equals( DesignChoiceConstants.SEARCH_TYPE_NONE );
			dteColumn.setSearchHint( searchHint );
		}
	}
	private IColumnDefinition newColumnDefn( ColumnHintHandle modelColumnHint )
	{