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
public static final String CHOICE_JOIN_TYPE = "joinType"; 
	public static final String JOIN_TYPE_INNER = "inner"; 
	public static final String JOIN_TYPE_LEFT_OUT = "left-out"; 
	public static final String JOIN_TYPE_RIGHT_OUT = "right-out"; 
	public static final String JOIN_TYPE_FULL_OUT = "full-out"; 
	/**
	 * joinOperator -- join operator of join condition.
	 */
	public static final String CHOICE_JOIN_OPERATOR = "joinOperator"; 
	public static final String JOIN_OPERATOR_EQALS = "eq"; 
	/**
	 * actionTargetFileType -- target type of the linked file
	 */
	public static final String CHOICE_ACTION_TARGET_FILE_TYPE = "actionTargetFileType"; 
	public static final String ACTION_TARGET_FILE_TYPE_REPORT_DESIGN = "report-design"; 
	public static final String ACTION_TARGET_FILE_TYPE_REPORT_DOCUMENT = "report-document"; 
	/**
	 * actionBookmarkType -- target bookmark type
	 */
	public static final String CHOICE_ACTION_BOOKMARK_TYPE = "actionBookmarkType"; 
	public static final String ACTION_BOOKMARK_TYPE_BOOKMARK = "bookmark"; 
	public static final String ACTION_BOOKMARK_TYPE_TOC = "toc"; 
	/**
	 * autotextType -- type of auto text
	 */
	public static final String CHOICE_AUTO_TEXT_TYPE = "autoTextType"; 
	public static final String AUTO_TEXT_PAGE_NUMBER = "page-number"; 
	public static final String AUTO_TEXT_TOTAL_PAGE = "total-page"; 
	/**
	 * dataSetMode -- the mode to support data sets. Can be single data set and