Fix https://issues.apache.org/bugzilla/show_bug.cgi?id=55383
Improve markup and design of the Tomcat 8 documentation webapp.
Patch provided by Konstantin Preißer.

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1517778 13f79535-47bb-0310-9956-ffa450edef68