[Screeninvader] [Janosh] ZMQ Support

[Amir Hassan]

i implemented zeromq support for janosh. that means scripts can now  
subscribe to key changes.

The following script waits for changes to the key /val and prints "hello"  
everytime it changes:

<code>
#!/usr/local/bin/janosh -f

function hello()
	print("hello")
end

Janosh:subscribe("/val", hello)
</code>

Note: you can subscribe to several keys in the same script.

greets,
amir