use latest sass and compass for testing
use latest middleman and compass for website
Ignore duplicate @import directives in Sass

Append Markdown for rendering only once per unique Sass source file.

Signed-off-by: Alex Coles <alex@alexbcoles.com>
added fixes from pull request into changelog
allow *.lsg and *.html.lsg files as source
fixed #90: error handling for undefined filters
make utf-8 work for ruby 1.9
version update