Template class and method with the NetworkStream parameters. Add upload action file.
Roll back to the hard coded network stream type (boost::asio::ip::tcp::iostream), it was far too early to template such a type...
Merge branch 'asio_umcd' of https://github.com/wesnoth/wesnoth-old into asio_umcd
Major architecture modification
Reason: The old architecture wasn't compatible with the asynchronous design of Boost.Asio
Modifications: Every actions are added to the io_service queue so each threads are equally used and not blocked for a long time.

* We don't use anymore the tcp::stream design because it doesn't scale with an asynchronous design.
* Add a license.txt file that escapes the quotes - Should be automatically created when the server start.
Scons build failed. CMake build is ok.