fixed a failing test case in normal testing mode.
bugfix: we did not get the request reference counter right when lua_need_request_body was turned on and nginx versions older than 1.2.6 or 1.2.9 were used.
updated tests to reflect recent changes in the DNS settings for my agentzh.org domain.
added (passing) tests for using ngx.req.read_body in the "rewrite" and "access" phases when nginx fails to send the "100 Continue" response.