Removed the signing key file to try to fix a problem for fresh clones. #58
Makes AggregateExceptionExtractor not extract exceptions if the assertion is against AggregateException (or subclass of AggregateException).
TypeExtensions.IsSameOrInherits fixed
moved TypeExtensionSpecs to 4.0 and 4.5 Specs projects
Allowed chaining additional assertions after asserting a document has an element with xDocument.Should().HaveElement(). #27