Statistics.xml: Remove summary statlet from collection home page

We learned that the CUA statlet at the collection level doesn't
aggregate hits for all items in the collection, and instead shows
the number of hits for the collection landing page itself. Because
this is kinda misleading I've removed it for now.
XMLUI: Revert to non-caching pipeline

This was an issue in DSpace 1.7/1.8... but we've got DSpace 4.2 plus
an entirely new JDK, Tomcat, Linux kernel, etc.  I'm reversing this
to see if the caching bug is still an issue.

Use the following command to do it:

	find dspace/modules/xmlui/src/main/webapp/themes -iname sitemap.xmap -exec sed -i 's/<map:pipeline type="noncaching">/<map:pipeline>/' {} \;