Version 0.18
- [added] support for CoAP-18
- [added] new layers and stack structure
- [added] new server and client APIs
- [added] datagram channels for data transmission
- [added] full configuration
- [improved] UDP transmission with SocketAsyncEventArgs for .NET 4+
- [improved] threading with TPL for .NET 4+
- [improved] logging with Common.Logging
- [fixed] lots of bugs