More tests.
More tests.

* test/test_buckets.c
  (read_and_check_bucket): Moved, no changes.
  (readline_and_check_bucket): New helper function to test results of
   serf_bucket_readline.
  (test_simple_bucket_readline): Add extra tests for all simple scenario's.
                                 Found bug!
  (test_aggregate_buckets): Fix comment.

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