exercises 1-4 for chapter 16

This will consume all of your CPU - probably a good idea to do something, even if it's just a sleep.
`$ perl -e "while(1){}" &
$ perl -e "while(1){sleep 1}" &`

![screen shot 2014-10-09 at 23 25 13](https://cloud.githubusercontent.com/assets/2790047/4585232/2b5e0358-5003-11e4-8068-66ec647339b6.png)