Always check that the test server was started successfully before starting the  actual test. This helps avoiding a segfault after one of the tests fails.
Always check that the test server was started successfully before starting the 
actual test. This helps avoiding a segfault after one of the tests fails.

* test/test_context.c
  (test_serf_closed_connection, 
   test_serf_setup_proxy,
   test_keepalive_limit_one_by_one,
   test_keepalive_limit_one_by_one_and_burst,
   test_serf_progress_callback): Assert that return value of test_server_create
    and apr_sockaddr_info_get is APR_SUCCESS.

jandre/serf,jandre/serf,jandre/serf,jandre/serf