Bug 210496 Add hasStyle property in reportItemModel extension point
When chart gets reportItem's properties by extending ReportItem, style properties are null. Hence, model needs to add hasStyle property in reportItemModel extension point
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/metadata/ElementDefn.java
*/
	public void addPropertyVisibility( String propName, String propVisibility )
	{
		if ( propVisibilites == null )
			propVisibilites = new HashMap( );
		propVisibilites.put( propName, propVisibility );
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.birt.report.model.api.metadata.IElementDefn#isPropertyReadOnly(java.lang.String)
	 */
	public boolean isPropertyReadOnly( String propName )
	{
		IPropertyDefn propDefn = getProperty( propName );
		if ( propDefn == null )
			return true;
		String visibility = getPropertyVisibility( propDefn.getName( ) );
		if ( READONLY_IN_PROPERTY_SHEET.equals( visibility ) )
			return true;
		return false;
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.birt.report.model.api.metadata.IElementDefn#isPropertyVisible(java.lang.String)
	 */
	public boolean isPropertyVisible( String propName )
	{
		IPropertyDefn propDefn = getProperty( propName );