[Cadenza] Allow EnumerableCoda.ToTuple() to work under .NET 4.0.
[Cadenza-Tests] Build Fix EnumerableCodaTest.ToTuple_TooManyValues() on .NET 4.0.

.NET 4.0 doesn't have a Tuple.MaxValues member, so don't use it.
Update .gitignore
Add Queue.DequeueOrDefault and TryDequeue
Fix namespace (and the build)
Add QueueCoda tests
Fix return value of CollectionCoda.RemoveAll
Add DictionaryCoda.TryRemove