Add configurable range_loop and stream_timeouts

Both new configurations are in milliseconds and in `riak_search`
sections. Configs are `range_loop_timeout` and `stream_timeout`
respectively.

Existing functions were left in just in case other code paths call the
collection paths.
Whitespace
Addressed PR comments
Add timeout argument to recursive call
Merge pull request #163 from basho/feature/bjs/range-loop-and-stream-timeouts

Add configurable range_loop and stream_timeouts