New chapter, and a package

We have released Sockets and Pipes chapter 10, "Change", which is about STM. We also published a library on Hackage to accompany the book.

The fourth draft of Sockets and Pipes is now available on Leanpub! It includes chapter 10, Change, which deals with using STM to add a stateful component to the web server.

Another new thing: We just published the sockets-and-pipes library on Hackage to accompany the book.

It re-exports the modules that we use, and so it ought to serve as a handy collecti…