Set the SLEEPFORDEBUGGER environment variable to the number of seconds a child
process should sleep before calling lok_init(), so that you have time to
attach the process in a debugger.
For now, each LOOL client has a separate child process (or none at all, if it
has accessed only information found in the cache). This will obviously have to
chnage to handle collaboration. Etc.
The parent process talks the same Websocket protocol with the child
processes. When there is a child process for a client, traffic from the client
is forwarded as such to the child process and vice versa.
