Added $font--family--mono
Replaced $white with $light and $black with $dark for code abstraction purposes.
Changed HTML5 validation colors
See extended description.

- Changed $color to $text and added darker alternatives.
- Passed  $color values to theme mixin.
- Changed theme mixin to generate .font--* instead of .theme--*.
Removed <meta> tag in <head> and trailing backslash in <link>