Rename Programmable Speaker

[teemu]

I think that the name and description of the speaker could be improved. The "programmable" doesn't really mean anything since everything in Factorio is programmable, like how we don't have a "Programmable power switch" but "Power switch".

Come to think of it, since the speaker actually depends on the circuit network, why not display an alert triangle when the speaker is unconnected so that the player knows that it's supposed to be connected in order to work?