Bug 299685 Empty iconURI's cause 'MalformedURLException' failures rather than being ignored
One of the issues Lars' found is that if you fill in a field (i.e. iconURI) and subsequently clear it you don't end up in the same model state. Once the value has been set in the editor it will never be 'null' again, clearing the field just sets it to an empty string.
bundles/org.eclipse.e4.ui.workbench.renderers.swt/src/org/eclipse/e4/workbench/ui/renderers/swt/SWTPartRenderer.java
*/
	protected void addLayoutForStyling(Composite composite) {
		GridLayout gl = new GridLayout(1, true);
		composite.setLayout(gl);
		gl.horizontalSpacing = 0;
		gl.verticalSpacing = 0;
		gl.marginHeight = 0;
		gl.marginWidth = 0;
	}
	/*
	 * HACK: Prep the control with layout information for the purpose of styling
	 * margins. See bug #280632
	 */
	protected void configureForStyling(Control control) {
		control.setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, true));
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see
	 * org.eclipse.e4.workbench.ui.renderers.AbstractPartRenderer#childRendered
	 * (org.eclipse.e4.ui.model.application.MElementContainer,
	 * org.eclipse.e4.ui.model.application.MUIElement)
	 */
	@Override
	public void childRendered(MElementContainer<MUIElement> parentElement,
			MUIElement element) {
	}
}