Bug 179674 Support time dimension in model
When define time dimension in model, the "itTime" property will be set. However this is not enough. We also need to know to what precision the time value should be evaluated, say, year, month, day, etc. Model needs to be enhanced to support such requirement.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/api/elements/DesignChoiceConstants.java
* Level type constants.
	 */
	String CHOICE_LEVEL_TYPE = "levelType"; 
	String LEVEL_TYPE_DYNAMIC = "dynamic"; 
	String LEVEL_TYPE_MIRRORED = "mirrored"; 
	
	/**
	 * measure Function -- measure function type.
	 */
	
	public static final String CHOICE_ACCESS_PERMISSION = "accessPermission"; 
	public static final String ACCESS_PERMISSION_ALLOW = "allow"; 
	public static final String ACCESS_PERMISSION_DISALLOW = "disallow"; 
		
	/**
	 * Parameter sort values -- can be value or display text.
	 */
	
	public static final String CHOICE_PARAM_SORT_VALUES = "paramSortValues"; 
	public static final String PARAM_SORT_VALUES_VALUE = "value"; 
	public static final String PARAM_SORT_VALUES_LABEL = "label"; 
	
	/**
	 * Report layout preference -- layout type for report design.
	 */
	public static final String CHOICE_REPORT_LAYOUT_PREFERENCE = "reportLayoutPreference"; 
	public static final String REPORT_LAYOUT_PREFERENCE_FIXED_LAYOUT = "fixed layout"; 
	public static final String REPORT_LAYOUT_PREFERENCE_AUTO_LAYOUT = "auto layout"; 
};