Pass LoginServlet's ServletContext to the Authenticators. When implementing SAML validation we need a way to configure a trusted key, and passing the ServletContext seems to be about the simplest way to do this.

<?xml version="1.0" encoding="UTF-8" ?>
<datacage>
    <user>SA</user>
    <password/>
    <driver>org.h2.Driver</driver>
    <url>jdbc:h2:${artifacts.config.dir}/../datacagedb/datacage</url>
</datacage>