These innocent toolbar menuContribution extensions seem to have been the
cause of the ConcurrentModificationException that came from inside
Eclipse code when this plug-in was in use and the Eclipse platform
version used was 4.5.2. It didn't happen on 4.5.1.
refs #6980
Change-Id: I279c1693ffa6bed1cec1400b3d9ec0f6f7189e3f
</extension>
+ <!--
<extension
point="org.eclipse.ui.menus">
<menuContribution
</toolbar>
</menuContribution>
</extension>
+ -->
<extension
point="org.eclipse.ui.commands">
<command