Add 'restart' instructions to Eclipse p2 installer.

website/templates/setup/eclipse.html

@@ -34,5 +34,7 @@
 			<br />
 			<img width="626" height="216" src="/img/eclipse-p2-step2.png" />
 		</p>
+		<p><strong>NB: You need to actually quit Eclipse and start it again; the regular restart is not good enough.</strong>
+		</p>
 	</@s.section>
 </@s.scaffold>