Drop Jetty servlets dependency to ensure smooth deployment on non-Jetty servers

After the discussion in hawtio/hawtio#1449, I have reworked this to remove the Jetty Servlets dependency.

There was also a problem with template path for startcontainer.html after pretty URLs were added to hawtio & Windows line endings (yuk).

Could this be released so the version of dockerui in fabric8io/fabric8/pom.xml can be updated? Current version annoyingly doesn't allow deletion of containers or images which this fixes.