Adding helper function to format a table from a nested list

Being able to easily write a table with columns adjusted appropriately seems to be a common usecase for the library, see [this](http://www.tedreed.info/programming/2012/06/02/how-to-use-textprettyprintboxes/) example. This function makes it very easy. For example:

```haskell
tbl = [["Stian", "1", "19.5"], ["Peter", "2", "21.55"], ["Alfred", "3", "99.1"]]
printBox $ formatTable [left, right, right] 2 tbl

Stian   1   19.5
Peter   2  21.55
Alfred  3   99.1
```

If you think including a function like this, I am very happy to polish it when it comes to which arguments it accepts, coding style etc. I personally think the lazy cycling of the align is neat, because it let's you supply just a single [left], and have that repeated for each column, but I don't know if it's good style.