Bug 136571 Drop property is displayed in Property Editor for all kinds of cells.
Description: Drop property displayed in Property Editor for all kinds of cells. Drop property is only supported by cells in group but it is listed in every kinds of cells even in grid cell which will mislead users.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/api/SimpleGroupElementHandle.java
baseDefn = elemDefn;
			if ( elemDefn != baseDefn )
				return false;
		}
		return true;
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.birt.report.model.api.GroupElementHandle#visiblePropertyIterator()
	 */
	public Iterator visiblePropertyIterator( )
	{
		List list = getCommonProperties( );
		final List visibleList = new ArrayList( );
		for ( int i = 0; i < list.size( ); i++ )
		{
			IElementPropertyDefn propDefn = (IElementPropertyDefn) list.get( i );
			if ( isPropertyVisible( propDefn.getName( ) ) )
			{
				visibleList.add( propDefn );
			}
		}
		return new GroupPropertyIterator( visibleList );
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.birt.report.model.api.GroupElementHandle#isPropertyVisible(java.lang.String)
	 */