Update README.md examples

[andrakis]

This corrects the examples in the README.md file so that they work out of the box.

It also adds a thread.kill() to the progression example so that the example finishes.

This resolves #17

[coveralls]

Coverage remained the same at 97.368% when pulling 20d3d28 on andrakis:update_examples into 80da634 on andywer:master.

[andywer]

Thank you! But I am just now writing a very small change, so you can use .on('done'), too, since it's pretty convenient.

I guess I will just revert that one line. .on('message') seems counter-intuitive for progress-reporting threads...