Clean up HAML.

- Add haml-lint config file to allow long lines. This is temporary
until I can find a HAML syntax highlighter that supports splitting
attributes on multiple lines.

- Clean up HAML to make haml-lint pass

- Convert application layout to HAML

- Fix bug that caused google translate initialization to time out. The
JS was looking for an ID called `google-translate-element`, but in the
layout it was called `google_translate_element`.

- Make description meta attribute localizable.
Move common partials to shared folder.

The Rails convention is to keep partials that are shared across all
pages inside either the `layouts` folder, or in a `shared` folder. I
prefer `shared` because it’s more explicit.

I also fixed the >IE8 conditional at the top of the application layout.
Merge pull request #543 from codeforamerica/convert-application-layout-to-haml

Clean up HAML.