remote-lively: getting started with a very simple session tracker
core: adding noninteractive option to World>>getUserName
remote-lively: simple session tracking and querying is working
lively-remote: unregister session && remote eval
network: adding simple wrapper around client WebSocket object (lively.net.WebSocket)
lively remote: using lively websockets for sessio ntracker
subservers: adding simple wrapper for server side web socket handler (manages connections)
lively remote: using server side socket handler for session tracker
lively remote: adding session tracker tests to default test suite
lively remote: getting started with session data federation
Merge pull request #136 from LivelyKernel/session-tracking

Lively remote

I'm merging this PR for now.
- The server/client websocket helpers are useful in themselves
- communication between Lively Worlds in the same Lively Realm works great
- session tracking of opt-in worlds also works

Yet to do:
- Sharing session data between Lively Realms
- Federation of inter-realm connections