SLING-3647 - No repository found at ... URL scheme http not supported.
only

Replaced usage of RepositoryBuilder with direct instantiation of the
single known RepositoryFactory implementation.

Also removed a couple of now-stable TODOs.

git-svn-id: https://svn.apache.org/repos/asf/sling/trunk@1602373 13f79535-47bb-0310-9956-ffa450edef68