Add support for complicated @import rules by passing them off to CSS.

This makes e.g. "@import url(fonts.css) all" work.

lib/sass/engine.rb

@@ -298,8 +298,9 @@ module Sass
     def parse_directive(line)
       directive, value = line[1..-1].split(/\s+/, 2)
 
-      case directive
-      when "import"
+      # If value begins with url( or ",
+      # it's a CSS @import rule and we don't want to touch it.
+      if directive == "import" && value !~ /^(url\(|")/
         import(value)
       else
         Tree::DirectiveNode.new(line, @options[:style])

test/sass/engine_test.rb

@@ -98,6 +98,11 @@ class SassEngineTest < Test::Unit::TestCase
     end
   end
 
+  def test_css_import
+    assert_equal("@import url(./fonts.css) screen;", render("@import url(./fonts.css) screen"))
+    assert_equal("@import \"./fonts.css\" screen;", render("@import \"./fonts.css\" screen"))
+  end
+
   def test_default_function
     assert_equal("foo {\n  bar: url(foo.png); }\n",
                  render("foo\n  bar = url(foo.png)\n"));