HAML configured to :ugly mode, does not insert indentation.
Revert "Converted layout from HAML to ERB."

This reverts commit 34ca937c264e34fef8a47bdb15ff2cbd04278b8f.
Revert "Converted whitespace-problematic templates from HAML to ERB."

This reverts commit 2d8db92febf903bae24bb3f83f73a63ab6f0871d.
Authentication HTTP example.
Validation Error HTTP example.
Representations section explains Link header.