[WIP] Automatic gettext calls on static texts in HAML

The **haml-magic-translations** gem automatically calls `_()` on all static texts in HAML files.
For string extraction see: https://github.com/potager/haml-magic-translations#extracting-strings-and-merging-translations
Escaping the single quote is fine... but should be escaping backslashes too. (Okay, they're relatively unlikely here, but incomplete escaping will always bite eventually.)

.. actually, why not just use `String#dump` or `String#inspect`?