Styling improvements with Sass and HTML changes

Made changes to site design to try to make it look cleaner.
I found that Open Sans web font looks better for text, so dropping Lora as my main body text font.
I'll see how that font works with block quotes and keep it for that.
Added colour background back in to the topbar, and added colour background to footer.

Also, amended the default rake task in Rakefile to build everything and preview.

Signed-off-by: Ippoippo <ippoippo_software@ippoippo.net>
Merge branch 'refs/heads/Improve_site_styling_with_scss_and_html_changes'