Bug 267117 [JFace] Provide possibility for subclasses to check if a column is visible in ViewerRow
Currently this is decided by checking with width but this makes Nebula-Grid fail.
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/ViewerRow.java
* Returns the location and bounds of the area where the image is drawn.
	 * 
	 * @param index
	 *            the column index
	 * @return the bounds of the of the image area. May return <code>null</code>
	 *         if the underlying widget implementation doesn't provide this
	 *         information
	 * @since 3.4
	 */
	public Rectangle getImageBounds(int index) {
		return null;
	}
	/**
	 * Set the style ranges to be applied on the text label at the column index
	 * Note: Requires {@link StyledCellLabelProvider} with owner draw enabled.
	 * 
	 * @param columnIndex
	 *            the index of the column
	 * @param styleRanges
	 *            the styled ranges
	 * 
	 * @since 3.4
	 */
	public void setStyleRanges(int columnIndex, StyleRange[] styleRanges) {
		getItem().setData(KEY_TEXT_LAYOUT + columnIndex, styleRanges);
	}
	/**
	 * Returns the style ranges to be applied on the text label at the column
	 * index or <code>null</code> if no style ranges have been set.
	 *