Fix the log4j configuration so that it is actually used.

Previously changes to WEB-INF/classes/log4j.xml had no effect because it was
not configured in web.xml.  This patch fixes this.
Improved logging configuration.

This configuration will log esg.search events to a separate file "esg-search.log".
It will also include the timestamp of each log entry which makes it much more useful.
Merge pull request #52 from cedadev/fix-log4j

Fix log4j