Use the new maven-publish with auth process for publication

This permits the use of Nexus or similar repository that has authentication requirements
Moved Gradle wrapper to 1.11 otherwise the build fails due to issues with dependencies on 1.6

I don't know if this will be of use to you - but because we have a mixed environment and maven supports encrypted passwords this is quite useful to us.

Let me know what you think.

Thanks,

Brett