Improved error reporting and version ordering

@jamesward this might merit a 0.1.0 release. Here's what Sonatype's guide says about allowing another user to publish:

> How does a new user ask for publish rights to existing repositories
Follow step 2, sign up and then leave a comment on the JIRA ticket with the username. We will assign related roles to him and update the ticket.

So maybe you have to do the first release, then create a ticket to ask them to allow me to release the artifact? My username there is mwanji.

Note: In the commit message about sisu-guice, I meant sisu-guava