Ensure delete preceeds update from SparqlIndexer

Resolves: https://www.pivotaltracker.com/story/show/83268844
Fix links in webapp index page

Resolves: https://www.pivotaltracker.com/story/show/83393356
[maven-release-plugin] prepare release fcrepo-message-consumer-4.0.0
[maven-release-plugin] prepare for next development iteration