Fix for ShouldContainOnlyInOrder EnumerableAssertion extension that was broken when the collections were of different lengths

`ShouldContainOnlyInOrder` works only when the expected and actual collections have the same lengths. When expected is longer than actual, misleading `ArgumentException` is thrown instead of `SpecificationException`. When expected is shorter than actual, the assertion passes, but it shouldn't. 

This pull requests fixes the method to cope with those scenarios, leaving the other method's characteristics not touched.