Add test for closing loud scripts

"Loud" script nodes aren’t being closed, and so the @script_stack_level
isn't popped correctly, causing parse errors:

    -if true
      =if true
        - 'A'
    -else
      B

gives "Syntax error on line 4: "else" is indented at wrong level:
expected 1, but was at 0."

test/parser_test.rb

@@ -76,6 +76,15 @@ module Haml
       end
     end
 
+    test "else after nested loud script is accepted" do
+      begin
+        parse "-if true\n  =if true\n    - 'A'\n-else\n  B"
+        assert true
+      rescue SyntaxError
+        flunk 'else after nested loud script should be accepted'
+      end
+    end
+
     private
 
     def parse(haml, options = nil)