Code formatting: add curly braces to if conditionals in unit tests
Use wp_get_theme() in unit tests

Change from get_current_theme() which is deprecated
See #62
Update theme tags in readme and style.css

Use the new 'responsive-layout' tag
Add 'translation-ready' and 'full-width-template'
Rename body class of legacy mode to 'thematic-xhtml'
Clarify inline hook doc of the `thematic_current_theme_layout` filter