Guava 15 skip CDI scanning

Guava 14 don't run in Wildfly, because `@Inject` annotation on Service class activates CDI. So Guava 15 have a beans.xml that disable scanning in managed environments.

I've tested musicjungle in Tomcat, Jetty, Glassfish and Wildfly, and all pages works fine.

Credits to @dipold, that discussed in dev mailing list about this guava issue first.