Do not emphasize first paragraph of each page

@jzimdars, @hsbt, @chikamichi

At the moment the first paragraph of each page has a bigger font size. We do not have a policy that first paragraphs always contain a summary of the page content, so this can lead to IMO quite irritating, unmotivated emphasis, see e.g.

![first-par](https://f.cloud.github.com/assets/1112299/1626568/fbb82af8-56e2-11e3-9892-b7d3dbfb8620.png)

The PR removes the special treatment of first paragraphs.