Update to PostSharp 3.1.28.
Revert "Update to NUnit.AddinsDependencies 2.6.3."

This reverts commit ff745382979bb5c5140400e3241ea024780e88b0.

Conflicts:
	solution/src/app/Testeroids/packages.config
	solution/src/test/Testeroids.Tests/packages.config

Causes TriangulatedFixtures to fail.
Revert "Update to NUnit 2.6.3."

This reverts commit c2a95e276d82d14646a3ad8003b0ca1e4acd82c7.

Conflicts:
	solution/src/app/Testeroids/Testeroids.nuspec
	solution/src/app/Testeroids/packages.config
	solution/src/test/Testeroids.Tests/packages.config

Causes TriangulatedFixtures to fail.