Blockquote styling changed

Re: Issue #[43](https://github.com/scala/scala.github.com/issues/43)

It's a pretty small change but I think it's an improvement.

I checked all existing uses and think it looks slightly better:

* `/conduct.html`
* `/overviews/reflection/symbols-trees-types.html`
* `/tutorials/tour/annotations.html`
* `/tutorials/tour/inner-classes.html`

I also made an example out of a recently added quote, reformatting as a blockquote.