Perhaps some kind of metal grid mounted over the windows, so that petrol bombs bursts outside, and cannot enter your house. The window and outer wall may catch fire, and plastic windows would eventually melt, but I'm sure that would be a nice compromise to burning to death. Also, I read an account somewhere about the economic collapse in, um, I think Argentina. The author talked about cinderblock outer walls saving him numerous times from petrol bombs.
Also, if the mesh over your windows projected about a foot away from the glass, I'm sure the fairly solid bottles would simply bounce off the mesh onto the ground.
Also, if the mesh over your windows projected about a foot away from the glass, I'm sure the fairly solid bottles would simply bounce off the mesh onto the ground.