Generalize and adapt riak_test to riak_core/pipe applications

[DeadZen]

Let's bring this age-old issue to a close..
Make it easier to test riak_core based applications, and so make it easier to contribute to essential riak components, a lot of these are just riak_kv hard codes that can be easily removed ..

basho/riak_test#260
basho/riak_test#609
basho/riak_test#752

it would be helpful to know how is riak being tested?
what performance/regression testing is being done for riak_kv, riak_core?
any available guidelines for developers to properly test (with cluster setup/tear down) these specific aspects locally?