Add riak_test for slf-n_val-sloppy_quorum-options.
Fix tests to use assert(false) instead of fail when not return value.
Work around riak_test bug by assert(false) instead of fail
Merge pull request #304 from basho/cet-n_val-sloppy_quorum-options

Add riak_test for slf-n_val-sloppy_quorum-options.