v0.0.3:
* Added utilities for sending Files over a stream. Accessable via require('tcp-stream-muxer').util.
* Added the util Function sendFile(filename, stream) to send the file filename over the stream stream
* Added the util Function receiveFile(filename, stream) to receive the file from the stream and save them to filename
* Added a second parameter to the createStream function. It is a callback that gets fired when the other site has created the stream.