Remove unused mixins
Add styles for archive component
Create button and links styles

* Refactor navigation with new method of applying button and correct
section colours.
* These colour modules can be extended into any class to apply either
foreground or background colour for a particular section.
Add button like titles to homepage archives
Add styles for post content
Add post navigation and authorship image to sidebar

* Tweak layout to ensure max-width of main content gives good
line-length.
* Add hire button and setting to footer
* Add image of me for linking back to Google Plus
Add icon font from existing site

* Add social icons to footer