Superfluous calls to base constructors

[ypiguet-epfl]

In dashel-posix.cpp and dashel-win32.cpp, constructors of Stream subclasses call explicitly the Stream constructor even when there is an intermediate class in the class hierarchy and they already call the Stream constructor indirectly. For example in dashel-posix.cpp, SocketStream::SocketStream calls both Stream("tcp") and DisconnectableStream("tcp") while DisconnectableStream::DisconnectableStream already calls Stream::Stream with the correct parameter.

[stephanemagnenat]

This looks stupid indeed. I am really wondering why we did it that way, there might have been a reason, but I cannot recall that. Maybe we changed the class hierarchy after an initial draft and this is just a historical left-over, or it was to work-around an old compiler bug?

We should clean it. What I miss in Dashel is a set of proper end-to-end tests. These could be simple, using ctest bundled with cmake, and should test basic behaviours of the different components. I've added an issue, #27.