minification; highlighting; blog root; response types; json; bootstrap; ...

+ whitespace fixes
+ minify jquery and foundation
+ don't hardcode blog root -- let the permalink specify it. (if this looks sane, i'll do another PR that updates mirage-www as required.)
+ add `Headers`, a set of handy default content return types
+ add `application/json` to `Headers`
+ add rudimentary bootstrap support alongside foundation
+ rationalisation of `feed.id`, generation of permalinks, etc.