[PATCH] dynamic scope should reflect chained scopes

DynamicScope ignores chaind scopes. Is'nt it bug?

For example, Post.a_pre_defined_scope.scoped_by_author_id(1) reflects only scoped_by_author_id scope, ignores a_pre_defined_scope.

Of course it also affetct 2 or more chained dynamic scope, Post.scoped_by_author_id(1).scoped_by_title("a title") ignores scoped_by_author_id.

I wrote a patch to fix this problem.