Add connection write timeout and rotate messages

- drop old messages when client is backlogged
- increase default server backlog
Add simple example using autobahn.js to connect to Turnpike

- issue #11
Add license (MIT)
Possible fix for autobahn.js changes
Reference package with full URL
Add newId function to generate a call ID.

See AutobahnPython Clinet implementation for reference:
https://github.com/tavendo/AutobahnPython/blob/master/autobahn/autobahn/util.py#L65
Merge remote-tracking branch 'upstream/dev' into mp-fix_examples
Merge remote-tracking branch 'upstream/dev' into mp-add_client_id_generator
Add callback on session open (WAMP welcome message)
Add example to documentation on how to use NewServer
Add documentation to most of the public API.
Merge branch 'mp-open_session_callbacks' into dev-mp
Merge branch 'mp-add_client_id_generator' into dev-mp

Conflicts:
	client.go
Merge branch 'mp-add_documentation' into dev-mp

Conflicts:
	client.go
	server.go
Fix bug where sessionOpenCallback was missing in struct
Export less methods to the API, fixes #16
Remove dependency on github.com/jcelliott/lumber for logging, fixes #13

This solution will not create any overhead when the debug flag is set
to false as the compiler will optimize all if statements.
See discussion: https://groups.google.com/forum/#!topic/golang-nuts/Qlxs3V77nss
Unify example presentation
Simplify and fix client example
Simplify server example