Check-point: changed to NUnit 2.6.2 to get around a bug in the latest version of NUnit and the NUnit VS test runner.
Revert "Check-point: changed to NUnit 2.6.2 to get around a bug in the latest version of NUnit and the NUnit VS test runner."  The runner seems to work fine with NUnit 2.6.3 as long as binding redirects have been added to the test project.

This reverts commit 79e2ec111fe06c44e48fa5ffc82670889bbad1f7.
Bumped for NuGet update.