Version 3.1.8

This release of dyn4j is a maintenance release to fix a bug in the Vector2.distance(double,double) method.  It also had a few methods added to the Body class to get BodyFixture(s) at a given world space point.  See the change detail in the release notes.

A new release of the Sandbox was published for this release due to changes in WebStart security and an API change by JOGL.