Add multiget implementation with a static worker pool.
Add multiget implementation with a static worker pool.

bmess/riak-python-client,basho/riak-python-client,basho/riak-python-client,GabrielNicolasAvellaneda/riak-python-client,GabrielNicolasAvellaneda/riak-python-client,basho/riak-python-client,bmess/riak-python-client