test that riak uses the correct search system for "search" mr inputs

Riak attempts to choose the correct search system (riak_search or
yokozuna) to provide MapReduce inputs when {search, Bucket, Query} is
specified. The `mapred_search_switch` test makes sure that the expected
system is chosen, given the cluster's configuration (whether riak_search
and yokozuna are each enabled, and whether the choice of which to use
has been set explicitly).
separate yz bucket name from index name

since they don't map 1:1, make sure the translation takes place

also add a wait for the index to become available before writing data
for it
check direct index mr search directly

to make sure that riak_search unmaps and that yokozuna doesn't remap
verify that yz bucket mr search only produces keys for that bucket

it will be translating the bucket search to an index search, but it
should also be filtering that index search by the bucket name
make riak_search default mapred search provider

if both riak_search and yokozuna are enabled, but the
riak_kv:mapred_search appenv has not been set, default to riak_search
use mochijson2 format for search mapred inputs

we have ripped out the earlier {index, Index} option to simplify things
rip out second bucket of data, because bucket filter is no longer used

yokozuna mapred_search no longer adds a bucket-name filter when
mapred-searching a bucket, so don't test for it working here
Update crypto call for 16B02
Ditch the crazy bucket vs. index idea

The "bucket" is the "index".  Chalk it up to poor naming make a long
time ago.  We're only human.
Merge pull request #387 from basho/feature/bwf/mr-switch

Test new MR Search Switch and "index" spec