Bugfix so the parser can handle an arbitrary number of terminal line comments.

document_parser.cpp

@@ -58,8 +58,11 @@ namespace Sass {
         root << parse_warning();
         if (!lex< exactly<';'> >()) throw_syntax_error("top-level @warn directive must be terminated by ';'");
       }
+      else if (lex< spaces_and_comments >()) {
+        continue;
+      }
       else {
-        lex< spaces_and_comments >();
+        while (peek< spaces_and_comments >()) lex< spaces_and_comments >();
         throw_syntax_error("invalid top-level expression");
       }
       lex< optional_spaces >();