Use correct reference to context through the importer
Use correct reference to context through the importer

Fixes #366 in the correct way, hopefully.

I can't cite my sources well, since Sprockets is very difficult to follow... but suffice to say the global options hash sent to the Tilt SASS template engine always has a reference to the Sprockets importer, and the importer always has a reference to the context. Tested with Sprockets 2.2.2 with and without Rails.

insight-meditation-center/imc-bootstrap-sass,insight-meditation-center/imc-bootstrap-sass,insight-meditation-center/imc-bootstrap-sass,insight-meditation-center/imc-bootstrap-sass