remove 2i TODO
remove 2i TODO

testing showed a 2i $key range query to be no more than 10% faster than
the filtered keylist query, and that test didn't include the extra
filtering necessary to account for 2i's inclusive range specification

laurenrother/riak_cs,GabrielNicolasAvellaneda/riak_cs,yangchengjian/riak_cs,basho/riak_cs_lfs,dragonfax/riak_cs,GabrielNicolasAvellaneda/riak_cs,basho/riak_cs,laurenrother/riak_cs,basho/riak_cs,basho/riak_cs,basho/riak_cs,sdebnath/riak_cs,yangchengjian/riak_cs,dragonfax/riak_cs,laurenrother/riak_cs,GabrielNicolasAvellaneda/riak_cs,sdebnath/riak_cs,yangchengjian/riak_cs,laurenrother/riak_cs,yangchengjian/riak_cs,dragonfax/riak_cs,basho/riak_cs_report,GabrielNicolasAvellaneda/riak_cs,sdebnath/riak_cs,sdebnath/riak_cs,dragonfax/riak_cs