SLING-3313 - actually use the seal() method to make the disposal callback list unmodifiable

git-svn-id: https://svn.apache.org/repos/asf/sling/trunk@1563046 13f79535-47bb-0310-9956-ffa450edef68
SLING-3335 - add a models configuration printer to see the currently registered injectors

git-svn-id: https://svn.apache.org/repos/asf/sling/trunk@1563047 13f79535-47bb-0310-9956-ffa450edef68
SLING-3334 - explicitly rank injectors

git-svn-id: https://svn.apache.org/repos/asf/sling/trunk@1563048 13f79535-47bb-0310-9956-ffa450edef68
SLING-3357 - allow a model class to have a single argument constructor which takes the adaptable as a parameter.

git-svn-id: https://svn.apache.org/repos/asf/sling/trunk@1563049 13f79535-47bb-0310-9956-ffa450edef68