Just bumped Isis version to 0.3.1-SNAPSHOT

[Dan Haywood <da...@haywood-associates.co.uk>]

.... ie, have got rid of the "-incubating" bit.

I've also been working through some of the release process steps, now
documented on our new website [1].  So, there are more files changed than
just the pom.xml's.    As usual, I've pushed these changes up to my github
clone (for anyone who might be working from that).

Also, I took the opportunity to implement the <DependencyConvergence> rule
by the maven-enforce-plugin.  This should improve build stability.

Thx
Dan


[1] http://isis.apache.org/contributors/release-process.html