[#29] Add some new code block definitions

Instead of using colour names, avoid ambiguity by using the scratch
block names as the code class names.
[#29] Add scratchblock styles to scss

Fixes 1d543ea9 because it was totally wrong.
Merge branch 'master' into 29-block-css

Conflicts:
	assets/css/master.min.css
Merge branch 'master' into 29-block-css

Conflicts:
	assets/css/master.min.css
Merge pull request #30 from andylolz/29-block-css

[#29] Add some new code block definitions