Use object initializer
Enable test that JSON serialize error is logged
Add failing ReferenceLoop tests
Upgrade to Json.NET 5.0.6

Note that this version of Json.NET does ship with a net45 version,
but it causes problems with ILMerge. Resolved by referencing net40.

See #451 for discussion.
Set Json.NET ReferenceLoopHandling = Ignore
Merge pull request #451 from dahlbyk/ReferenceLoop

Reference loop => JSON.NET 5.0.6