- rewrote jrebel intro

- added more comments to the code examples
- forgot, don't need to HTML escape ORG markup.
- added shebang
- new colours
- now push styles too

- some hardening to handling of generated directories
- added CSS class for favicon images to set the same size of the
  favicon. This is necessary because favicon no longer (?) are of a
  pre-definied, default size.

- made all favicon images in the footer use the new CSS class instead
  of hard coding it.