This is a patch for libmemcache-1.4.0.rc2.tar.bz2 to fix the mc_err_filter_* api.

The mc_err_filter_* are used in cmemcache to filter out notice messages for add/replace
that do not result in a store.

The patch also adds a full create result, get result, destroy result benchmark (run by
specifying G in the options to test/benchmark/benchmark).