Bug 205049 Other plug-ins should be able to define default content generator
Currently only the content generator can define which plug-ins it can be the default for - we need a way for plug-ins to refer back to the marker support for thier own generator.
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/provisional/views/markers/MarkerPriorityField.java
public MarkerPriorityField() {
		super();
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.ui.internal.provisional.views.markers.MarkerField#getValue(org.eclipse.ui.internal.provisional.views.markers.MarkerItem)
	 */
	public String getValue(MarkerItem item) {
		return MarkerSupportConstants.EMPTY_STRING;
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.ui.internal.provisional.views.markers.MarkerField#getColumnHeaderText()
	 */
	public String getColumnHeaderText() {
		return MarkerSupportConstants.EMPTY_STRING;
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.ui.internal.provisional.views.markers.api.MarkerField#getDefaultColumnWidth(org.eclipse.swt.widgets.Control)
	 */
	public int getDefaultColumnWidth(Control control) {
		return getHighPriorityImage().getBounds().width
				+ IDialogConstants.BUTTON_MARGIN;
	}
	/*
	 * (non-Javadoc)