Debian builds:

- Remove with-libtomcat6-java and with-libtomcat7-java
- Replace with-libjetty8-java with-libjetty9-java
- Add libtomcat8-java dependency in debian builds
- Change libservlet-3.0-java implicit dependency to libservlet-3.1-java
- Initial mods for trusty build files, as it does not have jetty 9
- Initial xenial build files
- Add link to jetty9-apache-jsp.jar
- Add necessary util jars to jsp classpath
Non-Debian builds:
- Move tomcat runtime from javax.servlet.jar to jasper-runtime.jar,
  to be consistent with Jetty 8
- Switch from jetty (glassfish) to apache (tomcat) jsp implementation,
  to be consistent with Debian builds
- Drop checked-in Tomcat 6 and Jetty 8 jars
Code:
- Force Jasper initialization in RouterConsoleRunner since we
  don't use the Jetty annotation scanner