SLING-4155, consider default injection strategy also for injector-specific annotations

by that deprecate isOptional on all injector-specific annotations and introduce the new injectionStrategy attribute as a replacement.

git-svn-id: https://svn.apache.org/repos/asf/sling/trunk@1640710 13f79535-47bb-0310-9956-ffa450edef68
SLING-3027 use latest releases (Sling Engine, Sling Servlets Resolver)

git-svn-id: https://svn.apache.org/repos/asf/sling/trunk@1640720 13f79535-47bb-0310-9956-ffa450edef68