A capstone example for Bioinformatics in R

The idea here is to show learners how to apply novice R lessons to bioinformatics. This is a very hastily prepared pull request for work in progress but contributions and suggestions very welcome!
`library("ggplot2")` is considered better style, for example in the JStatSoft guidelines. `ggplot2` doesn't exist as an object and how/why the unquoted form works may as well be magic to people at this stage. So from a consistency argument (why can't you do: `install.packages(ggplot2)` ? (rhetorical)) the quoted version is preferred.