Squeel can bind params for CollectionProxy in subquery correctly after Rails 4

Fix #312

Examples:

    before:

    Tag.from{first_article.tags.as(Tag.table_name)}.order{tags.name}.to_a
    # => returns error or []

    after:

    Tag.from{first_article.tags.as(Tag.table_name)}.order{tags.name}.to_a
    # => [<Tag>, <Tag>, <Tag>, ...]