Bug 203838 [Markers] [Markers] clicking on column headers does not sort table
I20070918 Clicking on any of the column headers does not sort based on the relevant column.
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/provisional/views/markers/CachedMarkerBuilder.java
updateJob.cancel();
				buildAllMarkers(monitor);
				updateJob.schedule();
				return Status.OK_STATUS;
			}
			/*
			 * (non-Javadoc)
			 * 
			 * @see org.eclipse.ui.progress.WorkbenchJob#shouldRun()
			 */
			public boolean shouldRun() {
				
				return PlatformUI.isWorkbenchRunning();
			}
		};
		markerProcessJob.setSystem(true);
	}
	/**
	 * Return the categories for the receiver.
	 * 
	 * @return MarkerCategory[] or <code>null</code> if there are no
	 *         categories.
	 */
	public MarkerCategory[] getCategories() {
		if (building) {
			return null;
		}
		return categories;
	}
	/**