Use render arrays instead of hardcoded markup

Hi, sorry for my bad english.

I have wrote a patch for use "render arrays" like drupal 7 best practise, but is my first attempt to drupal render feature.

I don't know if this is the correct path, but I need this patch for add custom classes to body and footer div, and for altering style attributes setted by admin panel in map.

This is only a proof of concept, but I hope this could be useful for someone.