Bugs:
  If an @imported document is changed, Sass should recompile the template
 
Testing:
  Test html2haml and css2sass
 
Documentation:
  Haml::Engine public method documentation could use work
  !! Document at-rules.
 
Features:
  Sass should throw generic errors for undefined constants, not syntax errors
  Sass::Plugin should log errors
  There should be a way to represent options in-document
  There should be a way to make Haml tags not insert whitespace
  "%li, %a"?
  Sass::Engine load_paths option should be set by executable