Squashed '.themes/whitespace/' changes from 08993a9..426ef4c

426ef4c Merge branch 'master' of https://github.com/lucaslew/whitespace
53b25bb Added new color for small headings

git-subtree-dir: .themes/whitespace
git-subtree-split: 426ef4cb2a64053c911776b460625c62f6561ae7
Merge commit 'd1d9bb229fe170a89fcd6a46bc6ff0f40d686364' into source

Pull https://github.com/lucaslew/whitespace to `.themes/whitespace`.
Apply whitespace theme

See
https://github.com/lucaslew/whitespace/commit/426ef4cb2a64053c911776b460625c62f6561ae7.