Bug 204935 [Markers] MarkersView should use fixed default widths
The MarkersView should use fixed rather than proportional widths as columns are getting very small when the workbench is restarted with a small markers view.
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/provisional/views/markers/ExtendedMarkersView.java
public boolean belongsTo(Object family) {
				return family == MarkerContentGenerator.CACHE_UPDATE_FAMILY;
			}
			/**
			 * Return the viewer that is being updated.
			 * 
			 * @return TreeViewer
			 */
			private TreeViewer getViewer() {
				return viewer;
			}
			/*
			 * (non-Javadoc)
			 * 
			 * @see org.eclipse.ui.progress.UIJob#runInUIThread(org.eclipse.core.runtime.IProgressMonitor)
			 */
			public IStatus runInUIThread(IProgressMonitor monitor) {
				if (viewer.getControl().isDisposed()) {
					return Status.CANCEL_STATUS;
				}
				if (monitor.isCanceled())
					return Status.CANCEL_STATUS;
				getViewer().refresh(true);
				updateTitle();
				if (preservedSelection.size() > 0) {
					Collection newSelection = new ArrayList();
					MarkerItem[] markerEntries = builder.getVisibleMarkers()
							.toArray();
					for (int i = 0; i < markerEntries.length; i++) {
						Iterator preserved = preservedSelection.iterator();