No real time clock

I tried to add a new configuration variable which allows the user to choose if the chat timestamps should be generated by the server or by the client's browser. This is useful if the device which runs the piratebox has no real time clock. To achive this I added a small javascript to send a timestamp with the chat message to the server. 
The configuration variable doesn't work yet, in order to use "os.environ" the variable has to be added to the env file in the directory conf/lighttpd.