Reboot & Type cleanup

Created by: MartijnCuppens

• Line height & font family from html were directly overridden by body, so I removed those
• The remaining properties are moved to body
• Shim for IE10 tags removed
• hr cleanup
  • Combined styles from reboot & _type.scss
  • Changed from borders to background
    • This allows us to keep the color inherited.
    • Opacity can be used to change the intensity
    • Size attribute will change the height instead of making the hr look like an input field
  • Better variable names
• headings cleanup
  • Moved all element styling to reboot. This was actually a bug because before our docs claimed we had different font sizes for headings
  • _type.scss will now extend the element styling. This way we will save some redundant code
• small & mark are also moved to reboot. _type.scss does not contain any element styling anymore
• font weight removed from small, this did not really made sense