SLING-2989 - [Tooling] integrate with vlt once available

Ensure that the JCR commands operate on a repository paths rather than
on platform paths. This still isn't the right level of abstraction, but
the Repository APIs will need an overhaul for this to work properly.

git-svn-id: https://svn.apache.org/repos/asf/sling/branches/tooling-ide-vlt@1522952 13f79535-47bb-0310-9956-ffa450edef68