Custom Authenticators

[Steve Appling]

In Tomcat 7 I could use the org.apache.catalina.startup.Embedded class'
addAuthenticator method to set up my own custom authenticators.  This
allowed me to define a new authenticator that a web-app could select with
<auth-method/> in web.xml.  Now that the Embedded class has been removed
(in 8), I'm not sure how to accomplish this.  Is there some way to add a
similar custom authenticator when using the Tomcat class?