Fix combo of compass-import-once and sass-globs. Closes middleman/middleman-sprockets#56
Fix after_render

Example usage from config.rb:

after_render do |content, path, locs, template_class|
  # restore character entities such as &amp;#96;
  content ||= ''
  content.gsub! '&amp;', '&'
  content
end
Merge pull request #1278 from bootstraponline/fix_after_render

Fix after_render
Fix tests after Padrino 0.12.2 release
Merge remote-tracking branch 'origin/v3-stable'

Conflicts:
	middleman-core/lib/middleman-core/core_extensions/rendering.rb
	middleman/middleman.gemspec